ETH Price: $2,063.60 (+9.00%)

Transaction Decoder

Block:
13208675 at Sep-12-2021 04:03:35 AM +UTC
Transaction Fee:
0.014015520860250299 ETH $28.92
Gas Used:
285,869 Gas / 49.027774471 Gwei

Emitted Events:

221 AdminUpgradeabilityProxy.0x8c5be1e5ebec7d5bd14f71427d1e84f3dd0314c0f7b2291e5b200ac8c7c3b925( 0x8c5be1e5ebec7d5bd14f71427d1e84f3dd0314c0f7b2291e5b200ac8c7c3b925, 0x00000000000000000000000026aa87d5df5504b370d4c3aa7852a416f5aab455, 0x0000000000000000000000000000000000000000000000000000000000000000, 0x00000000000000000000000000000000000000000000000000000000000148d4 )
222 AdminUpgradeabilityProxy.0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef( 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef, 0x00000000000000000000000026aa87d5df5504b370d4c3aa7852a416f5aab455, 0x000000000000000000000000cda72070e455bb31c7690a170224ce43623d0b6f, 0x00000000000000000000000000000000000000000000000000000000000148d4 )
223 AdminUpgradeabilityProxy.0x1062dd3b35f12b4064331244d00f40c1d4831965e4285654157a2409c6217cff( 0x1062dd3b35f12b4064331244d00f40c1d4831965e4285654157a2409c6217cff, 0x00000000000000000000000026aa87d5df5504b370d4c3aa7852a416f5aab455, 0x0000000000000000000000003b3ee1931dc30c1957379fac9aba94d1c48a5405, 0x00000000000000000000000000000000000000000000000000000000000148d4, 0000000000000000000000000000000000000000000000000000000000015180, 0000000000000000000000000000000000000000000000000000000000000384, 00000000000000000000000000000000000000000000000003782dace9d90000, 0000000000000000000000000000000000000000000000000000000000014fb1 )

Account State Difference:

  Address   Before After State Difference Code
0x26aA87d5...6f5aaB455
0.041140463597865588 Eth
Nonce: 2
0.027124942737615289 Eth
Nonce: 3
0.014015520860250299
0x3B3ee193...1C48a5405
(BeePool)
884.743563510657545463 Eth884.743992314157545463 Eth0.0004288035
0xcDA72070...3623d0B6f
(Foundation: Market)

Execution Trace

AdminUpgradeabilityProxy.4ce6931a( )
  • FNDNFTMarket.createReserveAuction( nftContract=0x3B3ee1931Dc30C1957379FAc9aba94D1C48a5405, tokenId=84180, reservePrice=250000000000000000 )
    • AdminUpgradeabilityProxy.23b872dd( )
      • FNDNFT721.transferFrom( from=0x26aA87d5dF5504b370D4C3AA7852A416f5aaB455, to=0xcDA72070E455bb31C7690a170224Ce43623d0B6f, tokenId=84180 )
        File 1 of 4: AdminUpgradeabilityProxy
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.6.0;
        import './UpgradeabilityProxy.sol';
        /**
         * @title AdminUpgradeabilityProxy
         * @dev This contract combines an upgradeability proxy with an authorization
         * mechanism for administrative tasks.
         * All external functions in this contract must be guarded by the
         * `ifAdmin` modifier. See ethereum/solidity#3864 for a Solidity
         * feature proposal that would enable this to be done automatically.
         */
        contract AdminUpgradeabilityProxy is UpgradeabilityProxy {
          /**
           * Contract constructor.
           * @param _logic address of the initial implementation.
           * @param _admin Address of the proxy administrator.
           * @param _data Data to send as msg.data to the implementation to initialize the proxied contract.
           * It should include the signature and the parameters of the function to be called, as described in
           * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
           * This parameter is optional, if no data is given the initialization call to proxied contract will be skipped.
           */
          constructor(address _logic, address _admin, bytes memory _data) UpgradeabilityProxy(_logic, _data) public payable {
            assert(ADMIN_SLOT == bytes32(uint256(keccak256('eip1967.proxy.admin')) - 1));
            _setAdmin(_admin);
          }
          /**
           * @dev Emitted when the administration has been transferred.
           * @param previousAdmin Address of the previous admin.
           * @param newAdmin Address of the new admin.
           */
          event AdminChanged(address previousAdmin, address newAdmin);
          /**
           * @dev Storage slot with the admin of the contract.
           * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
           * validated in the constructor.
           */
          bytes32 internal constant ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
          /**
           * @dev Modifier to check whether the `msg.sender` is the admin.
           * If it is, it will run the function. Otherwise, it will delegate the call
           * to the implementation.
           */
          modifier ifAdmin() {
            if (msg.sender == _admin()) {
              _;
            } else {
              _fallback();
            }
          }
          /**
           * @return The address of the proxy admin.
           */
          function admin() external ifAdmin returns (address) {
            return _admin();
          }
          /**
           * @return The address of the implementation.
           */
          function implementation() external ifAdmin returns (address) {
            return _implementation();
          }
          /**
           * @dev Changes the admin of the proxy.
           * Only the current admin can call this function.
           * @param newAdmin Address to transfer proxy administration to.
           */
          function changeAdmin(address newAdmin) external ifAdmin {
            require(newAdmin != address(0), "Cannot change the admin of a proxy to the zero address");
            emit AdminChanged(_admin(), newAdmin);
            _setAdmin(newAdmin);
          }
          /**
           * @dev Upgrade the backing implementation of the proxy.
           * Only the admin can call this function.
           * @param newImplementation Address of the new implementation.
           */
          function upgradeTo(address newImplementation) external ifAdmin {
            _upgradeTo(newImplementation);
          }
          /**
           * @dev Upgrade the backing implementation of the proxy and call a function
           * on the new implementation.
           * This is useful to initialize the proxied contract.
           * @param newImplementation Address of the new implementation.
           * @param data Data to send as msg.data in the low level call.
           * It should include the signature and the parameters of the function to be called, as described in
           * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
           */
          function upgradeToAndCall(address newImplementation, bytes calldata data) payable external ifAdmin {
            _upgradeTo(newImplementation);
            (bool success,) = newImplementation.delegatecall(data);
            require(success);
          }
          /**
           * @return adm The admin slot.
           */
          function _admin() internal view returns (address adm) {
            bytes32 slot = ADMIN_SLOT;
            assembly {
              adm := sload(slot)
            }
          }
          /**
           * @dev Sets the address of the proxy admin.
           * @param newAdmin Address of the new proxy admin.
           */
          function _setAdmin(address newAdmin) internal {
            bytes32 slot = ADMIN_SLOT;
            assembly {
              sstore(slot, newAdmin)
            }
          }
          /**
           * @dev Only fall back when the sender is not the admin.
           */
          function _willFallback() internal override virtual {
            require(msg.sender != _admin(), "Cannot call fallback function from the proxy admin");
            super._willFallback();
          }
        }
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.6.0;
        import './Proxy.sol';
        import '@openzeppelin/contracts/utils/Address.sol';
        /**
         * @title UpgradeabilityProxy
         * @dev This contract implements a proxy that allows to change the
         * implementation address to which it will delegate.
         * Such a change is called an implementation upgrade.
         */
        contract UpgradeabilityProxy is Proxy {
          /**
           * @dev Contract constructor.
           * @param _logic Address of the initial implementation.
           * @param _data Data to send as msg.data to the implementation to initialize the proxied contract.
           * It should include the signature and the parameters of the function to be called, as described in
           * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
           * This parameter is optional, if no data is given the initialization call to proxied contract will be skipped.
           */
          constructor(address _logic, bytes memory _data) public payable {
            assert(IMPLEMENTATION_SLOT == bytes32(uint256(keccak256('eip1967.proxy.implementation')) - 1));
            _setImplementation(_logic);
            if(_data.length > 0) {
              (bool success,) = _logic.delegatecall(_data);
              require(success);
            }
          }  
          /**
           * @dev Emitted when the implementation is upgraded.
           * @param implementation Address of the new implementation.
           */
          event Upgraded(address indexed implementation);
          /**
           * @dev Storage slot with the address of the current implementation.
           * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
           * validated in the constructor.
           */
          bytes32 internal constant IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
          /**
           * @dev Returns the current implementation.
           * @return impl Address of the current implementation
           */
          function _implementation() internal override view returns (address impl) {
            bytes32 slot = IMPLEMENTATION_SLOT;
            assembly {
              impl := sload(slot)
            }
          }
          /**
           * @dev Upgrades the proxy to a new implementation.
           * @param newImplementation Address of the new implementation.
           */
          function _upgradeTo(address newImplementation) internal {
            _setImplementation(newImplementation);
            emit Upgraded(newImplementation);
          }
          /**
           * @dev Sets the implementation address of the proxy.
           * @param newImplementation Address of the new implementation.
           */
          function _setImplementation(address newImplementation) internal {
            require(Address.isContract(newImplementation), "Cannot set a proxy implementation to a non-contract address");
            bytes32 slot = IMPLEMENTATION_SLOT;
            assembly {
              sstore(slot, newImplementation)
            }
          }
        }
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.6.0;
        /**
         * @title Proxy
         * @dev Implements delegation of calls to other contracts, with proper
         * forwarding of return values and bubbling of failures.
         * It defines a fallback function that delegates all calls to the address
         * returned by the abstract _implementation() internal function.
         */
        abstract contract Proxy {
          /**
           * @dev Fallback function.
           * Implemented entirely in `_fallback`.
           */
          fallback () payable external {
            _fallback();
          }
          /**
           * @dev Receive function.
           * Implemented entirely in `_fallback`.
           */
          receive () payable external {
            _fallback();
          }
          /**
           * @return The Address of the implementation.
           */
          function _implementation() internal virtual view returns (address);
          /**
           * @dev Delegates execution to an implementation contract.
           * This is a low level function that doesn't return to its internal call site.
           * It will return to the external caller whatever the implementation returns.
           * @param implementation Address to delegate.
           */
          function _delegate(address implementation) internal {
            assembly {
              // Copy msg.data. We take full control of memory in this inline assembly
              // block because it will not return to Solidity code. We overwrite the
              // Solidity scratch pad at memory position 0.
              calldatacopy(0, 0, calldatasize())
              // Call the implementation.
              // out and outsize are 0 because we don't know the size yet.
              let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)
              // Copy the returned data.
              returndatacopy(0, 0, returndatasize())
              switch result
              // delegatecall returns 0 on error.
              case 0 { revert(0, returndatasize()) }
              default { return(0, returndatasize()) }
            }
          }
          /**
           * @dev Function that is run as the first thing in the fallback function.
           * Can be redefined in derived contracts to add functionality.
           * Redefinitions must call super._willFallback().
           */
          function _willFallback() internal virtual {
          }
          /**
           * @dev fallback implementation.
           * Extracted to enable manual triggering.
           */
          function _fallback() internal {
            _willFallback();
            _delegate(_implementation());
          }
        }
        // SPDX-License-Identifier: MIT
        pragma solidity >=0.6.2 <0.8.0;
        /**
         * @dev Collection of functions related to the address type
         */
        library Address {
            /**
             * @dev Returns true if `account` is a contract.
             *
             * [IMPORTANT]
             * ====
             * It is unsafe to assume that an address for which this function returns
             * false is an externally-owned account (EOA) and not a contract.
             *
             * Among others, `isContract` will return false for the following
             * types of addresses:
             *
             *  - an externally-owned account
             *  - a contract in construction
             *  - an address where a contract will be created
             *  - an address where a contract lived, but was destroyed
             * ====
             */
            function isContract(address account) internal view returns (bool) {
                // This method relies on extcodesize, which returns 0 for contracts in
                // construction, since the code is only stored at the end of the
                // constructor execution.
                uint256 size;
                // solhint-disable-next-line no-inline-assembly
                assembly { size := extcodesize(account) }
                return size > 0;
            }
            /**
             * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
             * `recipient`, forwarding all available gas and reverting on errors.
             *
             * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
             * of certain opcodes, possibly making contracts go over the 2300 gas limit
             * imposed by `transfer`, making them unable to receive funds via
             * `transfer`. {sendValue} removes this limitation.
             *
             * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
             *
             * IMPORTANT: because control is transferred to `recipient`, care must be
             * taken to not create reentrancy vulnerabilities. Consider using
             * {ReentrancyGuard} or the
             * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
             */
            function sendValue(address payable recipient, uint256 amount) internal {
                require(address(this).balance >= amount, "Address: insufficient balance");
                // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
                (bool success, ) = recipient.call{ value: amount }("");
                require(success, "Address: unable to send value, recipient may have reverted");
            }
            /**
             * @dev Performs a Solidity function call using a low level `call`. A
             * plain`call` is an unsafe replacement for a function call: use this
             * function instead.
             *
             * If `target` reverts with a revert reason, it is bubbled up by this
             * function (like regular Solidity function calls).
             *
             * Returns the raw returned data. To convert to the expected return value,
             * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
             *
             * Requirements:
             *
             * - `target` must be a contract.
             * - calling `target` with `data` must not revert.
             *
             * _Available since v3.1._
             */
            function functionCall(address target, bytes memory data) internal returns (bytes memory) {
              return functionCall(target, data, "Address: low-level call failed");
            }
            /**
             * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
             * `errorMessage` as a fallback revert reason when `target` reverts.
             *
             * _Available since v3.1._
             */
            function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
                return functionCallWithValue(target, data, 0, errorMessage);
            }
            /**
             * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
             * but also transferring `value` wei to `target`.
             *
             * Requirements:
             *
             * - the calling contract must have an ETH balance of at least `value`.
             * - the called Solidity function must be `payable`.
             *
             * _Available since v3.1._
             */
            function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
                return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
            }
            /**
             * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
             * with `errorMessage` as a fallback revert reason when `target` reverts.
             *
             * _Available since v3.1._
             */
            function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
                require(address(this).balance >= value, "Address: insufficient balance for call");
                require(isContract(target), "Address: call to non-contract");
                // solhint-disable-next-line avoid-low-level-calls
                (bool success, bytes memory returndata) = target.call{ value: value }(data);
                return _verifyCallResult(success, returndata, errorMessage);
            }
            /**
             * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
             * but performing a static call.
             *
             * _Available since v3.3._
             */
            function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                return functionStaticCall(target, data, "Address: low-level static call failed");
            }
            /**
             * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
             * but performing a static call.
             *
             * _Available since v3.3._
             */
            function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
                require(isContract(target), "Address: static call to non-contract");
                // solhint-disable-next-line avoid-low-level-calls
                (bool success, bytes memory returndata) = target.staticcall(data);
                return _verifyCallResult(success, returndata, errorMessage);
            }
            function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
                if (success) {
                    return returndata;
                } else {
                    // Look for revert reason and bubble it up if present
                    if (returndata.length > 0) {
                        // The easiest way to bubble the revert reason is using memory via assembly
                        // solhint-disable-next-line no-inline-assembly
                        assembly {
                            let returndata_size := mload(returndata)
                            revert(add(32, returndata), returndata_size)
                        }
                    } else {
                        revert(errorMessage);
                    }
                }
            }
        }
        

        File 2 of 4: AdminUpgradeabilityProxy
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.6.0;
        import './UpgradeabilityProxy.sol';
        /**
         * @title AdminUpgradeabilityProxy
         * @dev This contract combines an upgradeability proxy with an authorization
         * mechanism for administrative tasks.
         * All external functions in this contract must be guarded by the
         * `ifAdmin` modifier. See ethereum/solidity#3864 for a Solidity
         * feature proposal that would enable this to be done automatically.
         */
        contract AdminUpgradeabilityProxy is UpgradeabilityProxy {
          /**
           * Contract constructor.
           * @param _logic address of the initial implementation.
           * @param _admin Address of the proxy administrator.
           * @param _data Data to send as msg.data to the implementation to initialize the proxied contract.
           * It should include the signature and the parameters of the function to be called, as described in
           * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
           * This parameter is optional, if no data is given the initialization call to proxied contract will be skipped.
           */
          constructor(address _logic, address _admin, bytes memory _data) UpgradeabilityProxy(_logic, _data) public payable {
            assert(ADMIN_SLOT == bytes32(uint256(keccak256('eip1967.proxy.admin')) - 1));
            _setAdmin(_admin);
          }
          /**
           * @dev Emitted when the administration has been transferred.
           * @param previousAdmin Address of the previous admin.
           * @param newAdmin Address of the new admin.
           */
          event AdminChanged(address previousAdmin, address newAdmin);
          /**
           * @dev Storage slot with the admin of the contract.
           * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
           * validated in the constructor.
           */
          bytes32 internal constant ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
          /**
           * @dev Modifier to check whether the `msg.sender` is the admin.
           * If it is, it will run the function. Otherwise, it will delegate the call
           * to the implementation.
           */
          modifier ifAdmin() {
            if (msg.sender == _admin()) {
              _;
            } else {
              _fallback();
            }
          }
          /**
           * @return The address of the proxy admin.
           */
          function admin() external ifAdmin returns (address) {
            return _admin();
          }
          /**
           * @return The address of the implementation.
           */
          function implementation() external ifAdmin returns (address) {
            return _implementation();
          }
          /**
           * @dev Changes the admin of the proxy.
           * Only the current admin can call this function.
           * @param newAdmin Address to transfer proxy administration to.
           */
          function changeAdmin(address newAdmin) external ifAdmin {
            require(newAdmin != address(0), "Cannot change the admin of a proxy to the zero address");
            emit AdminChanged(_admin(), newAdmin);
            _setAdmin(newAdmin);
          }
          /**
           * @dev Upgrade the backing implementation of the proxy.
           * Only the admin can call this function.
           * @param newImplementation Address of the new implementation.
           */
          function upgradeTo(address newImplementation) external ifAdmin {
            _upgradeTo(newImplementation);
          }
          /**
           * @dev Upgrade the backing implementation of the proxy and call a function
           * on the new implementation.
           * This is useful to initialize the proxied contract.
           * @param newImplementation Address of the new implementation.
           * @param data Data to send as msg.data in the low level call.
           * It should include the signature and the parameters of the function to be called, as described in
           * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
           */
          function upgradeToAndCall(address newImplementation, bytes calldata data) payable external ifAdmin {
            _upgradeTo(newImplementation);
            (bool success,) = newImplementation.delegatecall(data);
            require(success);
          }
          /**
           * @return adm The admin slot.
           */
          function _admin() internal view returns (address adm) {
            bytes32 slot = ADMIN_SLOT;
            assembly {
              adm := sload(slot)
            }
          }
          /**
           * @dev Sets the address of the proxy admin.
           * @param newAdmin Address of the new proxy admin.
           */
          function _setAdmin(address newAdmin) internal {
            bytes32 slot = ADMIN_SLOT;
            assembly {
              sstore(slot, newAdmin)
            }
          }
          /**
           * @dev Only fall back when the sender is not the admin.
           */
          function _willFallback() internal override virtual {
            require(msg.sender != _admin(), "Cannot call fallback function from the proxy admin");
            super._willFallback();
          }
        }
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.6.0;
        import './Proxy.sol';
        import '@openzeppelin/contracts/utils/Address.sol';
        /**
         * @title UpgradeabilityProxy
         * @dev This contract implements a proxy that allows to change the
         * implementation address to which it will delegate.
         * Such a change is called an implementation upgrade.
         */
        contract UpgradeabilityProxy is Proxy {
          /**
           * @dev Contract constructor.
           * @param _logic Address of the initial implementation.
           * @param _data Data to send as msg.data to the implementation to initialize the proxied contract.
           * It should include the signature and the parameters of the function to be called, as described in
           * https://solidity.readthedocs.io/en/v0.4.24/abi-spec.html#function-selector-and-argument-encoding.
           * This parameter is optional, if no data is given the initialization call to proxied contract will be skipped.
           */
          constructor(address _logic, bytes memory _data) public payable {
            assert(IMPLEMENTATION_SLOT == bytes32(uint256(keccak256('eip1967.proxy.implementation')) - 1));
            _setImplementation(_logic);
            if(_data.length > 0) {
              (bool success,) = _logic.delegatecall(_data);
              require(success);
            }
          }  
          /**
           * @dev Emitted when the implementation is upgraded.
           * @param implementation Address of the new implementation.
           */
          event Upgraded(address indexed implementation);
          /**
           * @dev Storage slot with the address of the current implementation.
           * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
           * validated in the constructor.
           */
          bytes32 internal constant IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
          /**
           * @dev Returns the current implementation.
           * @return impl Address of the current implementation
           */
          function _implementation() internal override view returns (address impl) {
            bytes32 slot = IMPLEMENTATION_SLOT;
            assembly {
              impl := sload(slot)
            }
          }
          /**
           * @dev Upgrades the proxy to a new implementation.
           * @param newImplementation Address of the new implementation.
           */
          function _upgradeTo(address newImplementation) internal {
            _setImplementation(newImplementation);
            emit Upgraded(newImplementation);
          }
          /**
           * @dev Sets the implementation address of the proxy.
           * @param newImplementation Address of the new implementation.
           */
          function _setImplementation(address newImplementation) internal {
            require(Address.isContract(newImplementation), "Cannot set a proxy implementation to a non-contract address");
            bytes32 slot = IMPLEMENTATION_SLOT;
            assembly {
              sstore(slot, newImplementation)
            }
          }
        }
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.6.0;
        /**
         * @title Proxy
         * @dev Implements delegation of calls to other contracts, with proper
         * forwarding of return values and bubbling of failures.
         * It defines a fallback function that delegates all calls to the address
         * returned by the abstract _implementation() internal function.
         */
        abstract contract Proxy {
          /**
           * @dev Fallback function.
           * Implemented entirely in `_fallback`.
           */
          fallback () payable external {
            _fallback();
          }
          /**
           * @dev Receive function.
           * Implemented entirely in `_fallback`.
           */
          receive () payable external {
            _fallback();
          }
          /**
           * @return The Address of the implementation.
           */
          function _implementation() internal virtual view returns (address);
          /**
           * @dev Delegates execution to an implementation contract.
           * This is a low level function that doesn't return to its internal call site.
           * It will return to the external caller whatever the implementation returns.
           * @param implementation Address to delegate.
           */
          function _delegate(address implementation) internal {
            assembly {
              // Copy msg.data. We take full control of memory in this inline assembly
              // block because it will not return to Solidity code. We overwrite the
              // Solidity scratch pad at memory position 0.
              calldatacopy(0, 0, calldatasize())
              // Call the implementation.
              // out and outsize are 0 because we don't know the size yet.
              let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)
              // Copy the returned data.
              returndatacopy(0, 0, returndatasize())
              switch result
              // delegatecall returns 0 on error.
              case 0 { revert(0, returndatasize()) }
              default { return(0, returndatasize()) }
            }
          }
          /**
           * @dev Function that is run as the first thing in the fallback function.
           * Can be redefined in derived contracts to add functionality.
           * Redefinitions must call super._willFallback().
           */
          function _willFallback() internal virtual {
          }
          /**
           * @dev fallback implementation.
           * Extracted to enable manual triggering.
           */
          function _fallback() internal {
            _willFallback();
            _delegate(_implementation());
          }
        }
        // SPDX-License-Identifier: MIT
        pragma solidity >=0.6.2 <0.8.0;
        /**
         * @dev Collection of functions related to the address type
         */
        library Address {
            /**
             * @dev Returns true if `account` is a contract.
             *
             * [IMPORTANT]
             * ====
             * It is unsafe to assume that an address for which this function returns
             * false is an externally-owned account (EOA) and not a contract.
             *
             * Among others, `isContract` will return false for the following
             * types of addresses:
             *
             *  - an externally-owned account
             *  - a contract in construction
             *  - an address where a contract will be created
             *  - an address where a contract lived, but was destroyed
             * ====
             */
            function isContract(address account) internal view returns (bool) {
                // This method relies on extcodesize, which returns 0 for contracts in
                // construction, since the code is only stored at the end of the
                // constructor execution.
                uint256 size;
                // solhint-disable-next-line no-inline-assembly
                assembly { size := extcodesize(account) }
                return size > 0;
            }
            /**
             * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
             * `recipient`, forwarding all available gas and reverting on errors.
             *
             * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
             * of certain opcodes, possibly making contracts go over the 2300 gas limit
             * imposed by `transfer`, making them unable to receive funds via
             * `transfer`. {sendValue} removes this limitation.
             *
             * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
             *
             * IMPORTANT: because control is transferred to `recipient`, care must be
             * taken to not create reentrancy vulnerabilities. Consider using
             * {ReentrancyGuard} or the
             * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
             */
            function sendValue(address payable recipient, uint256 amount) internal {
                require(address(this).balance >= amount, "Address: insufficient balance");
                // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
                (bool success, ) = recipient.call{ value: amount }("");
                require(success, "Address: unable to send value, recipient may have reverted");
            }
            /**
             * @dev Performs a Solidity function call using a low level `call`. A
             * plain`call` is an unsafe replacement for a function call: use this
             * function instead.
             *
             * If `target` reverts with a revert reason, it is bubbled up by this
             * function (like regular Solidity function calls).
             *
             * Returns the raw returned data. To convert to the expected return value,
             * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
             *
             * Requirements:
             *
             * - `target` must be a contract.
             * - calling `target` with `data` must not revert.
             *
             * _Available since v3.1._
             */
            function functionCall(address target, bytes memory data) internal returns (bytes memory) {
              return functionCall(target, data, "Address: low-level call failed");
            }
            /**
             * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
             * `errorMessage` as a fallback revert reason when `target` reverts.
             *
             * _Available since v3.1._
             */
            function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
                return functionCallWithValue(target, data, 0, errorMessage);
            }
            /**
             * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
             * but also transferring `value` wei to `target`.
             *
             * Requirements:
             *
             * - the calling contract must have an ETH balance of at least `value`.
             * - the called Solidity function must be `payable`.
             *
             * _Available since v3.1._
             */
            function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
                return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
            }
            /**
             * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
             * with `errorMessage` as a fallback revert reason when `target` reverts.
             *
             * _Available since v3.1._
             */
            function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
                require(address(this).balance >= value, "Address: insufficient balance for call");
                require(isContract(target), "Address: call to non-contract");
                // solhint-disable-next-line avoid-low-level-calls
                (bool success, bytes memory returndata) = target.call{ value: value }(data);
                return _verifyCallResult(success, returndata, errorMessage);
            }
            /**
             * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
             * but performing a static call.
             *
             * _Available since v3.3._
             */
            function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                return functionStaticCall(target, data, "Address: low-level static call failed");
            }
            /**
             * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
             * but performing a static call.
             *
             * _Available since v3.3._
             */
            function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
                require(isContract(target), "Address: static call to non-contract");
                // solhint-disable-next-line avoid-low-level-calls
                (bool success, bytes memory returndata) = target.staticcall(data);
                return _verifyCallResult(success, returndata, errorMessage);
            }
            function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
                if (success) {
                    return returndata;
                } else {
                    // Look for revert reason and bubble it up if present
                    if (returndata.length > 0) {
                        // The easiest way to bubble the revert reason is using memory via assembly
                        // solhint-disable-next-line no-inline-assembly
                        assembly {
                            let returndata_size := mload(returndata)
                            revert(add(32, returndata), returndata_size)
                        }
                    } else {
                        revert(errorMessage);
                    }
                }
            }
        }
        

        File 3 of 4: FNDNFTMarket
        /*
          ・
           * ★
              ・ 。
                 ・ ゚☆ 。
              * ★ ゚・。 *  。
                    * ☆ 。・゚*.。
                 ゚ *.。☆。★ ・
        ​
                              `                     .-:::::-.`              `-::---...```
                             `-:`               .:+ssssoooo++//:.`       .-/+shhhhhhhhhhhhhyyyssooo:
                            .--::.            .+ossso+/////++/:://-`   .////+shhhhhhhhhhhhhhhhhhhhhy
                          `-----::.         `/+////+++///+++/:--:/+/-  -////+shhhhhhhhhhhhhhhhhhhhhy
                         `------:::-`      `//-.``.-/+ooosso+:-.-/oso- -////+shhhhhhhhhhhhhhhhhhhhhy
                        .--------:::-`     :+:.`  .-/osyyyyyyso++syhyo.-////+shhhhhhhhhhhhhhhhhhhhhy
                      `-----------:::-.    +o+:-.-:/oyhhhhhhdhhhhhdddy:-////+shhhhhhhhhhhhhhhhhhhhhy
                     .------------::::--  `oys+/::/+shhhhhhhdddddddddy/-////+shhhhhhhhhhhhhhhhhhhhhy
                    .--------------:::::-` +ys+////+yhhhhhhhddddddddhy:-////+yhhhhhhhhhhhhhhhhhhhhhy
                  `----------------::::::-`.ss+/:::+oyhhhhhhhhhhhhhhho`-////+shhhhhhhhhhhhhhhhhhhhhy
                 .------------------:::::::.-so//::/+osyyyhhhhhhhhhys` -////+shhhhhhhhhhhhhhhhhhhhhy
               `.-------------------::/:::::..+o+////+oosssyyyyyyys+`  .////+shhhhhhhhhhhhhhhhhhhhhy
               .--------------------::/:::.`   -+o++++++oooosssss/.     `-//+shhhhhhhhhhhhhhhhhhhhyo
             .-------   ``````.......--`        `-/+ooooosso+/-`          `./++++///:::--...``hhhhyo
                                                      `````
           * 
              ・ 。
            ・  ゚☆ 。
              * ★ ゚・。 *  。
                    * ☆ 。・゚*.。
                 ゚ *.。☆。★ ・
            *  ゚。·*・。 ゚*
             ☆゚・。°*. ゚
          ・ ゚*。・゚★。
          ・ *゚。   *
         ・゚*。★・
         ☆∴。 *
        ・ 。
        */
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        pragma abicoder v2; // solhint-disable-line
        import "@openzeppelin/contracts-upgradeable/utils/ReentrancyGuardUpgradeable.sol";
        import "./mixins/FoundationTreasuryNode.sol";
        import "./mixins/roles/FoundationAdminRole.sol";
        import "./mixins/roles/FoundationOperatorRole.sol";
        import "./mixins/NFTMarketCore.sol";
        import "./mixins/SendValueWithFallbackWithdraw.sol";
        import "./mixins/NFTMarketCreators.sol";
        import "./mixins/NFTMarketFees.sol";
        import "./mixins/NFTMarketAuction.sol";
        import "./mixins/NFTMarketReserveAuction.sol";
        import "./mixins/AccountMigration.sol";
        import "./mixins/NFTMarketPrivateSale.sol";
        /**
         * @title A market for NFTs on Foundation.
         * @dev This top level file holds no data directly to ease future upgrades.
         */
        contract FNDNFTMarket is
          FoundationTreasuryNode,
          FoundationAdminRole,
          FoundationOperatorRole,
          AccountMigration,
          NFTMarketCore,
          ReentrancyGuardUpgradeable,
          NFTMarketCreators,
          SendValueWithFallbackWithdraw,
          NFTMarketFees,
          NFTMarketAuction,
          NFTMarketReserveAuction,
          NFTMarketPrivateSale
        {
          /**
           * @notice Called once to configure the contract after the initial deployment.
           * @dev This farms the initialize call out to inherited contracts as needed.
           */
          function initialize(address payable treasury) public initializer {
            FoundationTreasuryNode._initializeFoundationTreasuryNode(treasury);
            NFTMarketAuction._initializeNFTMarketAuction();
            NFTMarketReserveAuction._initializeNFTMarketReserveAuction();
          }
          /**
           * @notice Allows Foundation to update the market configuration.
           */
          function adminUpdateConfig(
            uint256 minPercentIncrementInBasisPoints,
            uint256 duration,
            uint256 primaryF8nFeeBasisPoints,
            uint256 secondaryF8nFeeBasisPoints,
            uint256 secondaryCreatorFeeBasisPoints
          ) public onlyFoundationAdmin {
            // It's okay to call _reinitialize multiple times, but it must be called at least once after upgrade
            _reinitialize();
            _updateReserveAuctionConfig(minPercentIncrementInBasisPoints, duration);
            _updateMarketFees(primaryF8nFeeBasisPoints, secondaryF8nFeeBasisPoints, secondaryCreatorFeeBasisPoints);
          }
          /**
           * @dev Checks who the seller for an NFT is, this will check escrow or return the current owner if not in escrow.
           * This is a no-op function required to avoid compile errors.
           */
          function _getSellerFor(address nftContract, uint256 tokenId)
            internal
            view
            virtual
            override(NFTMarketCore, NFTMarketReserveAuction)
            returns (address payable)
          {
            return super._getSellerFor(nftContract, tokenId);
          }
        }
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.7.0;
        import "../proxy/Initializable.sol";
        /**
         * @dev Contract module that helps prevent reentrant calls to a function.
         *
         * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
         * available, which can be applied to functions to make sure there are no nested
         * (reentrant) calls to them.
         *
         * Note that because there is a single `nonReentrant` guard, functions marked as
         * `nonReentrant` may not call one another. This can be worked around by making
         * those functions `private`, and then adding `external` `nonReentrant` entry
         * points to them.
         *
         * TIP: If you would like to learn more about reentrancy and alternative ways
         * to protect against it, check out our blog post
         * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
         */
        abstract contract ReentrancyGuardUpgradeable is Initializable {
            // Booleans are more expensive than uint256 or any type that takes up a full
            // word because each write operation emits an extra SLOAD to first read the
            // slot's contents, replace the bits taken up by the boolean, and then write
            // back. This is the compiler's defense against contract upgrades and
            // pointer aliasing, and it cannot be disabled.
            // The values being non-zero value makes deployment a bit more expensive,
            // but in exchange the refund on every call to nonReentrant will be lower in
            // amount. Since refunds are capped to a percentage of the total
            // transaction's gas, it is best to keep them low in cases like this one, to
            // increase the likelihood of the full refund coming into effect.
            uint256 private constant _NOT_ENTERED = 1;
            uint256 private constant _ENTERED = 2;
            uint256 private _status;
            function __ReentrancyGuard_init() internal initializer {
                __ReentrancyGuard_init_unchained();
            }
            function __ReentrancyGuard_init_unchained() internal initializer {
                _status = _NOT_ENTERED;
            }
            /**
             * @dev Prevents a contract from calling itself, directly or indirectly.
             * Calling a `nonReentrant` function from another `nonReentrant`
             * function is not supported. It is possible to prevent this from happening
             * by making the `nonReentrant` function external, and make it call a
             * `private` function that does the actual work.
             */
            modifier nonReentrant() {
                // On the first call to nonReentrant, _notEntered will be true
                require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
                // Any calls to nonReentrant after this point will fail
                _status = _ENTERED;
                _;
                // By storing the original value once again, a refund is triggered (see
                // https://eips.ethereum.org/EIPS/eip-2200)
                _status = _NOT_ENTERED;
            }
            uint256[49] private __gap;
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        import "@openzeppelin/contracts-upgradeable/proxy/Initializable.sol";
        import "@openzeppelin/contracts-upgradeable/utils/AddressUpgradeable.sol";
        /**
         * @notice A mixin that stores a reference to the Foundation treasury contract.
         */
        abstract contract FoundationTreasuryNode is Initializable {
          using AddressUpgradeable for address payable;
          address payable private treasury;
          /**
           * @dev Called once after the initial deployment to set the Foundation treasury address.
           */
          function _initializeFoundationTreasuryNode(address payable _treasury) internal initializer {
            require(_treasury.isContract(), "FoundationTreasuryNode: Address is not a contract");
            treasury = _treasury;
          }
          /**
           * @notice Returns the address of the Foundation treasury.
           */
          function getFoundationTreasury() public view returns (address payable) {
            return treasury;
          }
          // `______gap` is added to each mixin to allow adding new data slots or additional mixins in an upgrade-safe way.
          uint256[2000] private __gap;
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        import "../../interfaces/IAdminRole.sol";
        import "../FoundationTreasuryNode.sol";
        /**
         * @notice Allows a contract to leverage the admin role defined by the Foundation treasury.
         */
        abstract contract FoundationAdminRole is FoundationTreasuryNode {
          // This file uses 0 data slots (other than what's included via FoundationTreasuryNode)
          modifier onlyFoundationAdmin() {
            require(_isFoundationAdmin(), "FoundationAdminRole: caller does not have the Admin role");
            _;
          }
          function _isFoundationAdmin() internal view returns (bool) {
            return IAdminRole(getFoundationTreasury()).isAdmin(msg.sender);
          }
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        import "../../interfaces/IOperatorRole.sol";
        import "../FoundationTreasuryNode.sol";
        /**
         * @notice Allows a contract to leverage the operator role defined by the Foundation treasury.
         */
        abstract contract FoundationOperatorRole is FoundationTreasuryNode {
          // This file uses 0 data slots (other than what's included via FoundationTreasuryNode)
          function _isFoundationOperator() internal view returns (bool) {
            return IOperatorRole(getFoundationTreasury()).isOperator(msg.sender);
          }
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        import "@openzeppelin/contracts-upgradeable/token/ERC721/IERC721Upgradeable.sol";
        /**
         * @notice A place for common modifiers and functions used by various NFTMarket mixins, if any.
         * @dev This also leaves a gap which can be used to add a new mixin to the top of the inheritance tree.
         */
        abstract contract NFTMarketCore {
          /**
           * @dev If the auction did not have an escrowed seller to return, this falls back to return the current owner.
           * This allows functions to calculate the correct fees before the NFT has been listed in auction.
           */
          function _getSellerFor(address nftContract, uint256 tokenId) internal view virtual returns (address payable) {
            return payable(IERC721Upgradeable(nftContract).ownerOf(tokenId));
          }
          // 50 slots were consumed by adding ReentrancyGuardUpgradeable
          uint256[950] private ______gap;
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        import "@openzeppelin/contracts-upgradeable/utils/AddressUpgradeable.sol";
        import "@openzeppelin/contracts-upgradeable/math/SafeMathUpgradeable.sol";
        import "@openzeppelin/contracts-upgradeable/utils/ReentrancyGuardUpgradeable.sol";
        /**
         * @notice Attempt to send ETH and if the transfer fails or runs out of gas, store the balance
         * for future withdrawal instead.
         */
        abstract contract SendValueWithFallbackWithdraw is ReentrancyGuardUpgradeable {
          using AddressUpgradeable for address payable;
          using SafeMathUpgradeable for uint256;
          mapping(address => uint256) private pendingWithdrawals;
          event WithdrawPending(address indexed user, uint256 amount);
          event Withdrawal(address indexed user, uint256 amount);
          /**
           * @notice Returns how much funds are available for manual withdraw due to failed transfers.
           */
          function getPendingWithdrawal(address user) public view returns (uint256) {
            return pendingWithdrawals[user];
          }
          /**
           * @notice Allows a user to manually withdraw funds which originally failed to transfer to themselves.
           */
          function withdraw() public {
            withdrawFor(msg.sender);
          }
          /**
           * @notice Allows anyone to manually trigger a withdrawal of funds which originally failed to transfer for a user.
           */
          function withdrawFor(address payable user) public nonReentrant {
            uint256 amount = pendingWithdrawals[user];
            require(amount > 0, "No funds are pending withdrawal");
            pendingWithdrawals[user] = 0;
            user.sendValue(amount);
            emit Withdrawal(user, amount);
          }
          /**
           * @dev Attempt to send a user ETH with a reasonably low gas limit of 20k,
           * which is enough to send to contracts as well.
           */
          function _sendValueWithFallbackWithdrawWithLowGasLimit(address payable user, uint256 amount) internal {
            _sendValueWithFallbackWithdraw(user, amount, 20000);
          }
          /**
           * @dev Attempt to send a user or contract ETH with a moderate gas limit of 90k,
           * which is enough for a 5-way split.
           */
          function _sendValueWithFallbackWithdrawWithMediumGasLimit(address payable user, uint256 amount) internal {
            _sendValueWithFallbackWithdraw(user, amount, 210000);
          }
          /**
           * @dev Attempt to send a user or contract ETH and if it fails store the amount owned for later withdrawal.
           */
          function _sendValueWithFallbackWithdraw(
            address payable user,
            uint256 amount,
            uint256 gasLimit
          ) private {
            if (amount == 0) {
              return;
            }
            // Cap the gas to prevent consuming all available gas to block a tx from completing successfully
            // solhint-disable-next-line avoid-low-level-calls
            (bool success, ) = user.call{ value: amount, gas: gasLimit }("");
            if (!success) {
              // Record failed sends for a withdrawal later
              // Transfers could fail if sent to a multisig with non-trivial receiver logic
              // solhint-disable-next-line reentrancy
              pendingWithdrawals[user] = pendingWithdrawals[user].add(amount);
              emit WithdrawPending(user, amount);
            }
          }
          uint256[499] private ______gap;
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        import "../interfaces/IFNDNFT721.sol";
        import "@openzeppelin/contracts-upgradeable/utils/ReentrancyGuardUpgradeable.sol";
        /**
         * @notice A mixin for associating creators to NFTs.
         * @dev In the future this may store creators directly in order to support NFTs created on a different platform.
         */
        abstract contract NFTMarketCreators is
          ReentrancyGuardUpgradeable // Adding this unused mixin to help with linearization
        {
          /**
           * @dev If the creator is not available then 0x0 is returned. Downstream this indicates that the creator
           * fee should be sent to the current seller instead.
           * This may apply when selling NFTs that were not minted on Foundation.
           */
          function _getCreator(address nftContract, uint256 tokenId) internal view returns (address payable) {
            try IFNDNFT721(nftContract).tokenCreator(tokenId) returns (address payable creator) {
              return creator;
            } catch {
              return address(0);
            }
          }
          /**
           * @dev Returns the creator and a destination address for any payments to the creator,
           * returns address(0) if the creator is unknown.
           */
          function _getCreatorAndPaymentAddress(address nftContract, uint256 tokenId)
            internal
            view
            returns (address payable, address payable)
          {
            address payable creator = _getCreator(nftContract, tokenId);
            try IFNDNFT721(nftContract).getTokenCreatorPaymentAddress(tokenId) returns (
              address payable tokenCreatorPaymentAddress
            ) {
              if (tokenCreatorPaymentAddress != address(0)) {
                return (creator, tokenCreatorPaymentAddress);
              }
            } catch // solhint-disable-next-line no-empty-blocks
            {
              // Fall through to return (creator, creator) below
            }
            return (creator, creator);
          }
          // 500 slots were added via the new SendValueWithFallbackWithdraw mixin
          uint256[500] private ______gap;
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        import "@openzeppelin/contracts-upgradeable/math/SafeMathUpgradeable.sol";
        import "@openzeppelin/contracts-upgradeable/proxy/Initializable.sol";
        import "@openzeppelin/contracts-upgradeable/token/ERC721/IERC721Upgradeable.sol";
        import "./FoundationTreasuryNode.sol";
        import "./Constants.sol";
        import "./NFTMarketCore.sol";
        import "./NFTMarketCreators.sol";
        import "./SendValueWithFallbackWithdraw.sol";
        /**
         * @notice A mixin to distribute funds when an NFT is sold.
         */
        abstract contract NFTMarketFees is
          Constants,
          Initializable,
          FoundationTreasuryNode,
          NFTMarketCore,
          NFTMarketCreators,
          SendValueWithFallbackWithdraw
        {
          using SafeMathUpgradeable for uint256;
          uint256 private _primaryFoundationFeeBasisPoints;
          uint256 private _secondaryFoundationFeeBasisPoints;
          uint256 private _secondaryCreatorFeeBasisPoints;
          mapping(address => mapping(uint256 => bool)) private nftContractToTokenIdToFirstSaleCompleted;
          event MarketFeesUpdated(
            uint256 primaryFoundationFeeBasisPoints,
            uint256 secondaryFoundationFeeBasisPoints,
            uint256 secondaryCreatorFeeBasisPoints
          );
          /**
           * @notice Returns true if the given NFT has not been sold in this market previously and is being sold by the creator.
           */
          function getIsPrimary(address nftContract, uint256 tokenId) public view returns (bool) {
            address payable seller = _getSellerFor(nftContract, tokenId);
            return _getIsPrimary(nftContract, tokenId, _getCreator(nftContract, tokenId), seller);
          }
          /**
           * @dev A helper that determines if this is a primary sale given the current seller.
           * This is a minor optimization to use the seller if already known instead of making a redundant lookup call.
           */
          function _getIsPrimary(
            address nftContract,
            uint256 tokenId,
            address creator,
            address seller
          ) private view returns (bool) {
            return !nftContractToTokenIdToFirstSaleCompleted[nftContract][tokenId] && creator == seller;
          }
          /**
           * @notice Returns the current fee configuration in basis points.
           */
          function getFeeConfig()
            public
            view
            returns (
              uint256 primaryFoundationFeeBasisPoints,
              uint256 secondaryFoundationFeeBasisPoints,
              uint256 secondaryCreatorFeeBasisPoints
            )
          {
            return (_primaryFoundationFeeBasisPoints, _secondaryFoundationFeeBasisPoints, _secondaryCreatorFeeBasisPoints);
          }
          /**
           * @notice Returns how funds will be distributed for an Auction sale at the given price point.
           * @dev This is required for backwards compatibility with subgraph.
           */
          function getFees(
            address nftContract,
            uint256 tokenId,
            uint256 price
          )
            public
            view
            returns (
              uint256 foundationFee,
              uint256 creatorSecondaryFee,
              uint256 ownerRev
            )
          {
            address payable seller = _getSellerFor(nftContract, tokenId);
            (foundationFee, , creatorSecondaryFee, , ownerRev) = _getFees(nftContract, tokenId, seller, price);
          }
          /**
           * @dev Calculates how funds should be distributed for the given sale details.
           * If this is a primary sale, the creator revenue will appear as `ownerRev`.
           */
          function _getFees(
            address nftContract,
            uint256 tokenId,
            address payable seller,
            uint256 price
          )
            private
            view
            returns (
              uint256 foundationFee,
              address payable creatorSecondaryFeeTo,
              uint256 creatorSecondaryFee,
              address payable ownerRevTo,
              uint256 ownerRev
            )
          {
            // The tokenCreatorPaymentAddress replaces the creator as the fee recipient.
            (address payable creator, address payable tokenCreatorPaymentAddress) = _getCreatorAndPaymentAddress(
              nftContract,
              tokenId
            );
            uint256 foundationFeeBasisPoints;
            if (_getIsPrimary(nftContract, tokenId, creator, seller)) {
              foundationFeeBasisPoints = _primaryFoundationFeeBasisPoints;
              // On a primary sale, the creator is paid the remainder via `ownerRev`.
              ownerRevTo = tokenCreatorPaymentAddress;
            } else {
              foundationFeeBasisPoints = _secondaryFoundationFeeBasisPoints;
              // If there is no creator then funds go to the seller instead.
              if (tokenCreatorPaymentAddress != address(0)) {
                // SafeMath is not required when dividing by a constant value > 0.
                creatorSecondaryFee = price.mul(_secondaryCreatorFeeBasisPoints) / BASIS_POINTS;
                creatorSecondaryFeeTo = tokenCreatorPaymentAddress;
              }
              if (seller == creator) {
                ownerRevTo = tokenCreatorPaymentAddress;
              } else {
                ownerRevTo = seller;
              }
            }
            // SafeMath is not required when dividing by a constant value > 0.
            foundationFee = price.mul(foundationFeeBasisPoints) / BASIS_POINTS;
            ownerRev = price.sub(foundationFee).sub(creatorSecondaryFee);
          }
          /**
           * @dev Distributes funds to foundation, creator, and NFT owner after a sale.
           * This call will respect the creator's payment address if defined.
           */
          function _distributeFunds(
            address nftContract,
            uint256 tokenId,
            address payable seller,
            uint256 price
          )
            internal
            returns (
              uint256 foundationFee,
              uint256 creatorFee,
              uint256 ownerRev
            )
          {
            address payable creatorFeeTo;
            address payable ownerRevTo;
            (foundationFee, creatorFeeTo, creatorFee, ownerRevTo, ownerRev) = _getFees(nftContract, tokenId, seller, price);
            // Anytime fees are distributed that indicates the first sale is complete,
            // which will not change state during a secondary sale.
            // This must come after the `_getFees` call above as this state is considered in the function.
            nftContractToTokenIdToFirstSaleCompleted[nftContract][tokenId] = true;
            _sendValueWithFallbackWithdrawWithLowGasLimit(getFoundationTreasury(), foundationFee);
            _sendValueWithFallbackWithdrawWithMediumGasLimit(creatorFeeTo, creatorFee);
            _sendValueWithFallbackWithdrawWithMediumGasLimit(ownerRevTo, ownerRev);
          }
          /**
           * @notice Allows Foundation to change the market fees.
           */
          function _updateMarketFees(
            uint256 primaryFoundationFeeBasisPoints,
            uint256 secondaryFoundationFeeBasisPoints,
            uint256 secondaryCreatorFeeBasisPoints
          ) internal {
            require(primaryFoundationFeeBasisPoints < BASIS_POINTS, "NFTMarketFees: Fees >= 100%");
            require(
              secondaryFoundationFeeBasisPoints.add(secondaryCreatorFeeBasisPoints) < BASIS_POINTS,
              "NFTMarketFees: Fees >= 100%"
            );
            _primaryFoundationFeeBasisPoints = primaryFoundationFeeBasisPoints;
            _secondaryFoundationFeeBasisPoints = secondaryFoundationFeeBasisPoints;
            _secondaryCreatorFeeBasisPoints = secondaryCreatorFeeBasisPoints;
            emit MarketFeesUpdated(
              primaryFoundationFeeBasisPoints,
              secondaryFoundationFeeBasisPoints,
              secondaryCreatorFeeBasisPoints
            );
          }
          uint256[1000] private ______gap;
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        /**
         * @notice An abstraction layer for auctions.
         * @dev This contract can be expanded with reusable calls and data as more auction types are added.
         */
        abstract contract NFTMarketAuction {
          /**
           * @dev A global id for auctions of any type.
           */
          uint256 private nextAuctionId;
          function _initializeNFTMarketAuction() internal {
            nextAuctionId = 1;
          }
          function _getNextAndIncrementAuctionId() internal returns (uint256) {
            return nextAuctionId++;
          }
          uint256[1000] private ______gap;
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        pragma abicoder v2; // solhint-disable-line
        import "@openzeppelin/contracts-upgradeable/math/SafeMathUpgradeable.sol";
        import "@openzeppelin/contracts-upgradeable/token/ERC721/IERC721Upgradeable.sol";
        import "@openzeppelin/contracts-upgradeable/utils/ReentrancyGuardUpgradeable.sol";
        import "./Constants.sol";
        import "./NFTMarketCore.sol";
        import "./NFTMarketFees.sol";
        import "./SendValueWithFallbackWithdraw.sol";
        import "./NFTMarketAuction.sol";
        import "./roles/FoundationAdminRole.sol";
        import "./AccountMigration.sol";
        /**
         * @notice Manages a reserve price auction for NFTs.
         */
        abstract contract NFTMarketReserveAuction is
          Constants,
          FoundationAdminRole,
          AccountMigration,
          NFTMarketCore,
          ReentrancyGuardUpgradeable,
          SendValueWithFallbackWithdraw,
          NFTMarketFees,
          NFTMarketAuction
        {
          using SafeMathUpgradeable for uint256;
          struct ReserveAuction {
            address nftContract;
            uint256 tokenId;
            address payable seller;
            uint256 duration;
            uint256 extensionDuration;
            uint256 endTime;
            address payable bidder;
            uint256 amount;
          }
          mapping(address => mapping(uint256 => uint256)) private nftContractToTokenIdToAuctionId;
          mapping(uint256 => ReserveAuction) private auctionIdToAuction;
          uint256 private _minPercentIncrementInBasisPoints;
          // This variable was used in an older version of the contract, left here as a gap to ensure upgrade compatibility
          uint256 private ______gap_was_maxBidIncrementRequirement;
          uint256 private _duration;
          // These variables were used in an older version of the contract, left here as gaps to ensure upgrade compatibility
          uint256 private ______gap_was_extensionDuration;
          uint256 private ______gap_was_goLiveDate;
          // Cap the max duration so that overflows will not occur
          uint256 private constant MAX_MAX_DURATION = 1000 days;
          uint256 private constant EXTENSION_DURATION = 15 minutes;
          event ReserveAuctionConfigUpdated(
            uint256 minPercentIncrementInBasisPoints,
            uint256 maxBidIncrementRequirement,
            uint256 duration,
            uint256 extensionDuration,
            uint256 goLiveDate
          );
          event ReserveAuctionCreated(
            address indexed seller,
            address indexed nftContract,
            uint256 indexed tokenId,
            uint256 duration,
            uint256 extensionDuration,
            uint256 reservePrice,
            uint256 auctionId
          );
          event ReserveAuctionUpdated(uint256 indexed auctionId, uint256 reservePrice);
          event ReserveAuctionCanceled(uint256 indexed auctionId);
          event ReserveAuctionBidPlaced(uint256 indexed auctionId, address indexed bidder, uint256 amount, uint256 endTime);
          event ReserveAuctionFinalized(
            uint256 indexed auctionId,
            address indexed seller,
            address indexed bidder,
            uint256 f8nFee,
            uint256 creatorFee,
            uint256 ownerRev
          );
          event ReserveAuctionCanceledByAdmin(uint256 indexed auctionId, string reason);
          event ReserveAuctionSellerMigrated(
            uint256 indexed auctionId,
            address indexed originalSellerAddress,
            address indexed newSellerAddress
          );
          modifier onlyValidAuctionConfig(uint256 reservePrice) {
            require(reservePrice > 0, "NFTMarketReserveAuction: Reserve price must be at least 1 wei");
            _;
          }
          /**
           * @notice Returns auction details for a given auctionId.
           */
          function getReserveAuction(uint256 auctionId) public view returns (ReserveAuction memory) {
            return auctionIdToAuction[auctionId];
          }
          /**
           * @notice Returns the auctionId for a given NFT, or 0 if no auction is found.
           * @dev If an auction is canceled, it will not be returned. However the auction may be over and pending finalization.
           */
          function getReserveAuctionIdFor(address nftContract, uint256 tokenId) public view returns (uint256) {
            return nftContractToTokenIdToAuctionId[nftContract][tokenId];
          }
          /**
           * @dev Returns the seller that put a given NFT into escrow,
           * or bubbles the call up to check the current owner if the NFT is not currently in escrow.
           */
          function _getSellerFor(address nftContract, uint256 tokenId)
            internal
            view
            virtual
            override
            returns (address payable seller)
          {
            seller = auctionIdToAuction[nftContractToTokenIdToAuctionId[nftContract][tokenId]].seller;
            if (seller == address(0)) {
              return super._getSellerFor(nftContract, tokenId);
            }
          }
          /**
           * @notice Returns the current configuration for reserve auctions.
           */
          function getReserveAuctionConfig() public view returns (uint256 minPercentIncrementInBasisPoints, uint256 duration) {
            minPercentIncrementInBasisPoints = _minPercentIncrementInBasisPoints;
            duration = _duration;
          }
          function _initializeNFTMarketReserveAuction() internal {
            _duration = 24 hours; // A sensible default value
          }
          function _updateReserveAuctionConfig(uint256 minPercentIncrementInBasisPoints, uint256 duration) internal {
            require(minPercentIncrementInBasisPoints <= BASIS_POINTS, "NFTMarketReserveAuction: Min increment must be <= 100%");
            // Cap the max duration so that overflows will not occur
            require(duration <= MAX_MAX_DURATION, "NFTMarketReserveAuction: Duration must be <= 1000 days");
            require(duration >= EXTENSION_DURATION, "NFTMarketReserveAuction: Duration must be >= EXTENSION_DURATION");
            _minPercentIncrementInBasisPoints = minPercentIncrementInBasisPoints;
            _duration = duration;
            // We continue to emit unused configuration variables to simplify the subgraph integration.
            emit ReserveAuctionConfigUpdated(minPercentIncrementInBasisPoints, 0, duration, EXTENSION_DURATION, 0);
          }
          /**
           * @notice Creates an auction for the given NFT.
           * The NFT is held in escrow until the auction is finalized or canceled.
           */
          function createReserveAuction(
            address nftContract,
            uint256 tokenId,
            uint256 reservePrice
          ) public onlyValidAuctionConfig(reservePrice) nonReentrant {
            // If an auction is already in progress then the NFT would be in escrow and the modifier would have failed
            uint256 auctionId = _getNextAndIncrementAuctionId();
            nftContractToTokenIdToAuctionId[nftContract][tokenId] = auctionId;
            auctionIdToAuction[auctionId] = ReserveAuction(
              nftContract,
              tokenId,
              msg.sender,
              _duration,
              EXTENSION_DURATION,
              0, // endTime is only known once the reserve price is met
              address(0), // bidder is only known once a bid has been placed
              reservePrice
            );
            IERC721Upgradeable(nftContract).transferFrom(msg.sender, address(this), tokenId);
            emit ReserveAuctionCreated(
              msg.sender,
              nftContract,
              tokenId,
              _duration,
              EXTENSION_DURATION,
              reservePrice,
              auctionId
            );
          }
          /**
           * @notice If an auction has been created but has not yet received bids, the configuration
           * such as the reservePrice may be changed by the seller.
           */
          function updateReserveAuction(uint256 auctionId, uint256 reservePrice) public onlyValidAuctionConfig(reservePrice) {
            ReserveAuction storage auction = auctionIdToAuction[auctionId];
            require(auction.seller == msg.sender, "NFTMarketReserveAuction: Not your auction");
            require(auction.endTime == 0, "NFTMarketReserveAuction: Auction in progress");
            auction.amount = reservePrice;
            emit ReserveAuctionUpdated(auctionId, reservePrice);
          }
          /**
           * @notice If an auction has been created but has not yet received bids, it may be canceled by the seller.
           * The NFT is returned to the seller from escrow.
           */
          function cancelReserveAuction(uint256 auctionId) public nonReentrant {
            ReserveAuction memory auction = auctionIdToAuction[auctionId];
            require(auction.seller == msg.sender, "NFTMarketReserveAuction: Not your auction");
            require(auction.endTime == 0, "NFTMarketReserveAuction: Auction in progress");
            delete nftContractToTokenIdToAuctionId[auction.nftContract][auction.tokenId];
            delete auctionIdToAuction[auctionId];
            IERC721Upgradeable(auction.nftContract).transferFrom(address(this), auction.seller, auction.tokenId);
            emit ReserveAuctionCanceled(auctionId);
          }
          /**
           * @notice A bidder may place a bid which is at least the value defined by `getMinBidAmount`.
           * If this is the first bid on the auction, the countdown will begin.
           * If there is already an outstanding bid, the previous bidder will be refunded at this time
           * and if the bid is placed in the final moments of the auction, the countdown may be extended.
           */
          function placeBid(uint256 auctionId) public payable nonReentrant {
            ReserveAuction storage auction = auctionIdToAuction[auctionId];
            require(auction.amount != 0, "NFTMarketReserveAuction: Auction not found");
            if (auction.endTime == 0) {
              // If this is the first bid, ensure it's >= the reserve price
              require(auction.amount <= msg.value, "NFTMarketReserveAuction: Bid must be at least the reserve price");
            } else {
              // If this bid outbids another, confirm that the bid is at least x% greater than the last
              require(auction.endTime >= block.timestamp, "NFTMarketReserveAuction: Auction is over");
              require(auction.bidder != msg.sender, "NFTMarketReserveAuction: You already have an outstanding bid");
              uint256 minAmount = _getMinBidAmountForReserveAuction(auction.amount);
              require(msg.value >= minAmount, "NFTMarketReserveAuction: Bid amount too low");
            }
            if (auction.endTime == 0) {
              auction.amount = msg.value;
              auction.bidder = msg.sender;
              // On the first bid, the endTime is now + duration
              auction.endTime = block.timestamp + auction.duration;
            } else {
              // Cache and update bidder state before a possible reentrancy (via the value transfer)
              uint256 originalAmount = auction.amount;
              address payable originalBidder = auction.bidder;
              auction.amount = msg.value;
              auction.bidder = msg.sender;
              // When a bid outbids another, check to see if a time extension should apply.
              if (auction.endTime - block.timestamp < auction.extensionDuration) {
                auction.endTime = block.timestamp + auction.extensionDuration;
              }
              // Refund the previous bidder
              _sendValueWithFallbackWithdrawWithLowGasLimit(originalBidder, originalAmount);
            }
            emit ReserveAuctionBidPlaced(auctionId, msg.sender, msg.value, auction.endTime);
          }
          /**
           * @notice Once the countdown has expired for an auction, anyone can settle the auction.
           * This will send the NFT to the highest bidder and distribute funds.
           */
          function finalizeReserveAuction(uint256 auctionId) public nonReentrant {
            ReserveAuction memory auction = auctionIdToAuction[auctionId];
            require(auction.endTime > 0, "NFTMarketReserveAuction: Auction was already settled");
            require(auction.endTime < block.timestamp, "NFTMarketReserveAuction: Auction still in progress");
            delete nftContractToTokenIdToAuctionId[auction.nftContract][auction.tokenId];
            delete auctionIdToAuction[auctionId];
            IERC721Upgradeable(auction.nftContract).transferFrom(address(this), auction.bidder, auction.tokenId);
            (uint256 f8nFee, uint256 creatorFee, uint256 ownerRev) = _distributeFunds(
              auction.nftContract,
              auction.tokenId,
              auction.seller,
              auction.amount
            );
            emit ReserveAuctionFinalized(auctionId, auction.seller, auction.bidder, f8nFee, creatorFee, ownerRev);
          }
          /**
           * @notice Returns the minimum amount a bidder must spend to participate in an auction.
           */
          function getMinBidAmount(uint256 auctionId) public view returns (uint256) {
            ReserveAuction storage auction = auctionIdToAuction[auctionId];
            if (auction.endTime == 0) {
              return auction.amount;
            }
            return _getMinBidAmountForReserveAuction(auction.amount);
          }
          /**
           * @dev Determines the minimum bid amount when outbidding another user.
           */
          function _getMinBidAmountForReserveAuction(uint256 currentBidAmount) private view returns (uint256) {
            uint256 minIncrement = currentBidAmount.mul(_minPercentIncrementInBasisPoints) / BASIS_POINTS;
            if (minIncrement == 0) {
              // The next bid must be at least 1 wei greater than the current.
              return currentBidAmount.add(1);
            }
            return minIncrement.add(currentBidAmount);
          }
          /**
           * @notice Allows Foundation to cancel an auction, refunding the bidder and returning the NFT to the seller.
           * This should only be used for extreme cases such as DMCA takedown requests. The reason should always be provided.
           */
          function adminCancelReserveAuction(uint256 auctionId, string memory reason) public onlyFoundationAdmin {
            require(bytes(reason).length > 0, "NFTMarketReserveAuction: Include a reason for this cancellation");
            ReserveAuction memory auction = auctionIdToAuction[auctionId];
            require(auction.amount > 0, "NFTMarketReserveAuction: Auction not found");
            delete nftContractToTokenIdToAuctionId[auction.nftContract][auction.tokenId];
            delete auctionIdToAuction[auctionId];
            IERC721Upgradeable(auction.nftContract).transferFrom(address(this), auction.seller, auction.tokenId);
            if (auction.bidder != address(0)) {
              _sendValueWithFallbackWithdrawWithMediumGasLimit(auction.bidder, auction.amount);
            }
            emit ReserveAuctionCanceledByAdmin(auctionId, reason);
          }
          /**
           * @notice Allows an NFT owner and Foundation to work together in order to update the seller
           * for auctions they have listed to a new account.
           * @param signature Message `I authorize Foundation to migrate my account to ${newAccount.address.toLowerCase()}`
           * signed by the original account.
           * @dev This will gracefully skip any auctions that have already been finalized.
           */
          function adminAccountMigration(
            uint256[] calldata listedAuctionIds,
            address originalAddress,
            address payable newAddress,
            bytes calldata signature
          ) public onlyAuthorizedAccountMigration(originalAddress, newAddress, signature) {
            for (uint256 i = 0; i < listedAuctionIds.length; i++) {
              uint256 auctionId = listedAuctionIds[i];
              ReserveAuction storage auction = auctionIdToAuction[auctionId];
              // The seller would be 0 if it was finalized before this call
              if (auction.seller != address(0)) {
                require(auction.seller == originalAddress, "NFTMarketReserveAuction: Auction not created by that address");
                auction.seller = newAddress;
                emit ReserveAuctionSellerMigrated(auctionId, originalAddress, newAddress);
              }
            }
          }
          uint256[1000] private ______gap;
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        import "@openzeppelin/contracts/cryptography/ECDSA.sol";
        import "@openzeppelin/contracts/utils/Address.sol";
        import "@openzeppelin/contracts/utils/Strings.sol";
        import "./roles/FoundationOperatorRole.sol";
        import "../interfaces/IERC1271.sol";
        /**
         * @notice Checks for a valid signature authorizing the migration of an account to a new address.
         * @dev This is shared by both the FNDNFT721 and FNDNFTMarket, and the same signature authorizes both.
         */
        abstract contract AccountMigration is FoundationOperatorRole {
          // From https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v4.1.0/contracts/utils/cryptography
          function _isValidSignatureNow(
            address signer,
            bytes32 hash,
            bytes memory signature
          ) private view returns (bool) {
            if (Address.isContract(signer)) {
              try IERC1271(signer).isValidSignature(hash, signature) returns (bytes4 magicValue) {
                return magicValue == IERC1271(signer).isValidSignature.selector;
              } catch {
                return false;
              }
            } else {
              return ECDSA.recover(hash, signature) == signer;
            }
          }
          // From https://ethereum.stackexchange.com/questions/8346/convert-address-to-string
          function _toAsciiString(address x) private pure returns (string memory) {
            bytes memory s = new bytes(42);
            s[0] = "0";
            s[1] = "x";
            for (uint256 i = 0; i < 20; i++) {
              bytes1 b = bytes1(uint8(uint256(uint160(x)) / (2**(8 * (19 - i)))));
              bytes1 hi = bytes1(uint8(b) / 16);
              bytes1 lo = bytes1(uint8(b) - 16 * uint8(hi));
              s[2 * i + 2] = _char(hi);
              s[2 * i + 3] = _char(lo);
            }
            return string(s);
          }
          function _char(bytes1 b) private pure returns (bytes1 c) {
            if (uint8(b) < 10) return bytes1(uint8(b) + 0x30);
            else return bytes1(uint8(b) + 0x57);
          }
          // From https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v4.1.0/contracts/utils/cryptography/ECDSA.sol
          // Modified to accept messages (instead of the message hash)
          function _toEthSignedMessage(bytes memory message) private pure returns (bytes32) {
            return keccak256(abi.encodePacked("\\x19Ethereum Signed Message:\
        ", Strings.toString(message.length), message));
          }
          /**
           * @dev Confirms the msg.sender is a Foundation operator and that the signature provided is valid.
           * @param signature Message `I authorize Foundation to migrate my account to ${newAccount.address.toLowerCase()}`
           * signed by the original account.
           */
          modifier onlyAuthorizedAccountMigration(
            address originalAddress,
            address newAddress,
            bytes memory signature
          ) {
            require(_isFoundationOperator(), "AccountMigration: Caller is not an operator");
            require(originalAddress != newAddress, "AccountMigration: Cannot migrate to the same account");
            bytes32 hash = _toEthSignedMessage(
              abi.encodePacked("I authorize Foundation to migrate my account to ", _toAsciiString(newAddress))
            );
            require(
              _isValidSignatureNow(originalAddress, hash, signature),
              "AccountMigration: Signature must be from the original account"
            );
            _;
          }
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        import "@openzeppelin/contracts-upgradeable/token/ERC721/IERC721Upgradeable.sol";
        import "./NFTMarketFees.sol";
        /**
         * @notice Adds support for a private sale of an NFT directly between two parties.
         */
        abstract contract NFTMarketPrivateSale is NFTMarketFees {
          /**
           * @dev This name is used in the EIP-712 domain.
           * If multiple classes use EIP-712 signatures in the future this can move to the shared constants file.
           */
          string private constant NAME = "FNDNFTMarket";
          /**
           * @dev This is a hash of the method signature used in the EIP-712 signature for private sales.
           */
          bytes32 private constant BUY_FROM_PRIVATE_SALE_TYPEHASH =
            keccak256("BuyFromPrivateSale(address nftContract,uint256 tokenId,address buyer,uint256 price,uint256 deadline)");
          /**
           * @dev This is the domain used in EIP-712 signatures.
           * It is not a constant so that the chainId can be determined dynamically.
           * If multiple classes use EIP-712 signatures in the future this can move to a shared file.
           */
          bytes32 private DOMAIN_SEPARATOR;
          event PrivateSaleFinalized(
            address indexed nftContract,
            uint256 indexed tokenId,
            address indexed seller,
            address buyer,
            uint256 f8nFee,
            uint256 creatorFee,
            uint256 ownerRev,
            uint256 deadline
          );
          /**
           * @dev This function must be called at least once before signatures will work as expected.
           * It's okay to call this function many times. Subsequent calls will have no impact.
           */
          function _reinitialize() internal {
            uint256 chainId;
            // solhint-disable-next-line no-inline-assembly
            assembly {
              chainId := chainid()
            }
            DOMAIN_SEPARATOR = keccak256(
              abi.encode(
                keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"),
                keccak256(bytes(NAME)),
                keccak256(bytes("1")),
                chainId,
                address(this)
              )
            );
          }
          /**
           * @notice Allow two parties to execute a private sale.
           * @dev The seller signs a message approving the sale, and then the buyer calls this function
           * with the msg.value equal to the agreed upon price.
           * The sale is executed in this single on-chain call including the transfer of funds and the NFT.
           */
          function buyFromPrivateSale(
            IERC721Upgradeable nftContract,
            uint256 tokenId,
            uint256 deadline,
            uint8 v,
            bytes32 r,
            bytes32 s
          ) public payable {
            // The seller must have the NFT in their wallet when this function is called.
            address payable seller = payable(nftContract.ownerOf(tokenId));
            // The signed message from the seller is only valid for a limited time.
            require(deadline >= block.timestamp, "NFTMarketPrivateSale: EXPIRED");
            // Scoping this block to avoid a stack too deep error
            {
              bytes32 digest = keccak256(
                abi.encodePacked(
                  "\\x19\\x01",
                  DOMAIN_SEPARATOR,
                  keccak256(abi.encode(BUY_FROM_PRIVATE_SALE_TYPEHASH, nftContract, tokenId, msg.sender, msg.value, deadline))
                )
              );
              // Revert if the signature is invalid, the terms are not as expected, or if the seller transferred the NFT.
              require(ecrecover(digest, v, r, s) == seller, "NFTMarketPrivateSale: INVALID_SIGNATURE");
            }
            // This will revert if the seller has not given the market contract approval.
            nftContract.transferFrom(seller, msg.sender, tokenId);
            // Pay the seller, creator, and Foundation as appropriate.
            (uint256 f8nFee, uint256 creatorFee, uint256 ownerRev) = _distributeFunds(
              address(nftContract),
              tokenId,
              seller,
              msg.value
            );
            emit PrivateSaleFinalized(
              address(nftContract),
              tokenId,
              seller,
              msg.sender,
              f8nFee,
              creatorFee,
              ownerRev,
              deadline
            );
          }
          uint256[1000] private ______gap;
        }
        // SPDX-License-Identifier: MIT
        // solhint-disable-next-line compiler-version
        pragma solidity >=0.4.24 <0.8.0;
        import "../utils/AddressUpgradeable.sol";
        /**
         * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
         * behind a proxy. Since a proxied contract can't have a constructor, it's common to move constructor logic to an
         * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
         * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
         *
         * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
         * possible by providing the encoded function call as the `_data` argument to {UpgradeableProxy-constructor}.
         *
         * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
         * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
         */
        abstract contract Initializable {
            /**
             * @dev Indicates that the contract has been initialized.
             */
            bool private _initialized;
            /**
             * @dev Indicates that the contract is in the process of being initialized.
             */
            bool private _initializing;
            /**
             * @dev Modifier to protect an initializer function from being invoked twice.
             */
            modifier initializer() {
                require(_initializing || _isConstructor() || !_initialized, "Initializable: contract is already initialized");
                bool isTopLevelCall = !_initializing;
                if (isTopLevelCall) {
                    _initializing = true;
                    _initialized = true;
                }
                _;
                if (isTopLevelCall) {
                    _initializing = false;
                }
            }
            /// @dev Returns true if and only if the function is running in the constructor
            function _isConstructor() private view returns (bool) {
                return !AddressUpgradeable.isContract(address(this));
            }
        }
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.7.0;
        /**
         * @dev Collection of functions related to the address type
         */
        library AddressUpgradeable {
            /**
             * @dev Returns true if `account` is a contract.
             *
             * [IMPORTANT]
             * ====
             * It is unsafe to assume that an address for which this function returns
             * false is an externally-owned account (EOA) and not a contract.
             *
             * Among others, `isContract` will return false for the following
             * types of addresses:
             *
             *  - an externally-owned account
             *  - a contract in construction
             *  - an address where a contract will be created
             *  - an address where a contract lived, but was destroyed
             * ====
             */
            function isContract(address account) internal view returns (bool) {
                // This method relies on extcodesize, which returns 0 for contracts in
                // construction, since the code is only stored at the end of the
                // constructor execution.
                uint256 size;
                // solhint-disable-next-line no-inline-assembly
                assembly { size := extcodesize(account) }
                return size > 0;
            }
            /**
             * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
             * `recipient`, forwarding all available gas and reverting on errors.
             *
             * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
             * of certain opcodes, possibly making contracts go over the 2300 gas limit
             * imposed by `transfer`, making them unable to receive funds via
             * `transfer`. {sendValue} removes this limitation.
             *
             * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
             *
             * IMPORTANT: because control is transferred to `recipient`, care must be
             * taken to not create reentrancy vulnerabilities. Consider using
             * {ReentrancyGuard} or the
             * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
             */
            function sendValue(address payable recipient, uint256 amount) internal {
                require(address(this).balance >= amount, "Address: insufficient balance");
                // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
                (bool success, ) = recipient.call{ value: amount }("");
                require(success, "Address: unable to send value, recipient may have reverted");
            }
            /**
             * @dev Performs a Solidity function call using a low level `call`. A
             * plain`call` is an unsafe replacement for a function call: use this
             * function instead.
             *
             * If `target` reverts with a revert reason, it is bubbled up by this
             * function (like regular Solidity function calls).
             *
             * Returns the raw returned data. To convert to the expected return value,
             * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
             *
             * Requirements:
             *
             * - `target` must be a contract.
             * - calling `target` with `data` must not revert.
             *
             * _Available since v3.1._
             */
            function functionCall(address target, bytes memory data) internal returns (bytes memory) {
              return functionCall(target, data, "Address: low-level call failed");
            }
            /**
             * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
             * `errorMessage` as a fallback revert reason when `target` reverts.
             *
             * _Available since v3.1._
             */
            function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
                return functionCallWithValue(target, data, 0, errorMessage);
            }
            /**
             * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
             * but also transferring `value` wei to `target`.
             *
             * Requirements:
             *
             * - the calling contract must have an ETH balance of at least `value`.
             * - the called Solidity function must be `payable`.
             *
             * _Available since v3.1._
             */
            function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
                return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
            }
            /**
             * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
             * with `errorMessage` as a fallback revert reason when `target` reverts.
             *
             * _Available since v3.1._
             */
            function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
                require(address(this).balance >= value, "Address: insufficient balance for call");
                require(isContract(target), "Address: call to non-contract");
                // solhint-disable-next-line avoid-low-level-calls
                (bool success, bytes memory returndata) = target.call{ value: value }(data);
                return _verifyCallResult(success, returndata, errorMessage);
            }
            /**
             * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
             * but performing a static call.
             *
             * _Available since v3.3._
             */
            function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                return functionStaticCall(target, data, "Address: low-level static call failed");
            }
            /**
             * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
             * but performing a static call.
             *
             * _Available since v3.3._
             */
            function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
                require(isContract(target), "Address: static call to non-contract");
                // solhint-disable-next-line avoid-low-level-calls
                (bool success, bytes memory returndata) = target.staticcall(data);
                return _verifyCallResult(success, returndata, errorMessage);
            }
            function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
                if (success) {
                    return returndata;
                } else {
                    // Look for revert reason and bubble it up if present
                    if (returndata.length > 0) {
                        // The easiest way to bubble the revert reason is using memory via assembly
                        // solhint-disable-next-line no-inline-assembly
                        assembly {
                            let returndata_size := mload(returndata)
                            revert(add(32, returndata), returndata_size)
                        }
                    } else {
                        revert(errorMessage);
                    }
                }
            }
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        /**
         * @notice Interface for AdminRole which wraps the default admin role from
         * OpenZeppelin's AccessControl for easy integration.
         */
        interface IAdminRole {
          function isAdmin(address account) external view returns (bool);
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        /**
         * @notice Interface for OperatorRole which wraps a role from
         * OpenZeppelin's AccessControl for easy integration.
         */
        interface IOperatorRole {
          function isOperator(address account) external view returns (bool);
        }
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.7.0;
        import "../../introspection/IERC165Upgradeable.sol";
        /**
         * @dev Required interface of an ERC721 compliant contract.
         */
        interface IERC721Upgradeable is IERC165Upgradeable {
            /**
             * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
             */
            event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
            /**
             * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
             */
            event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
            /**
             * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
             */
            event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
            /**
             * @dev Returns the number of tokens in ``owner``'s account.
             */
            function balanceOf(address owner) external view returns (uint256 balance);
            /**
             * @dev Returns the owner of the `tokenId` token.
             *
             * Requirements:
             *
             * - `tokenId` must exist.
             */
            function ownerOf(uint256 tokenId) external view returns (address owner);
            /**
             * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
             * are aware of the ERC721 protocol to prevent tokens from being forever locked.
             *
             * Requirements:
             *
             * - `from` cannot be the zero address.
             * - `to` cannot be the zero address.
             * - `tokenId` token must exist and be owned by `from`.
             * - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
             * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
             *
             * Emits a {Transfer} event.
             */
            function safeTransferFrom(address from, address to, uint256 tokenId) external;
            /**
             * @dev Transfers `tokenId` token from `from` to `to`.
             *
             * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
             *
             * Requirements:
             *
             * - `from` cannot be the zero address.
             * - `to` cannot be the zero address.
             * - `tokenId` token must be owned by `from`.
             * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
             *
             * Emits a {Transfer} event.
             */
            function transferFrom(address from, address to, uint256 tokenId) external;
            /**
             * @dev Gives permission to `to` to transfer `tokenId` token to another account.
             * The approval is cleared when the token is transferred.
             *
             * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
             *
             * Requirements:
             *
             * - The caller must own the token or be an approved operator.
             * - `tokenId` must exist.
             *
             * Emits an {Approval} event.
             */
            function approve(address to, uint256 tokenId) external;
            /**
             * @dev Returns the account approved for `tokenId` token.
             *
             * Requirements:
             *
             * - `tokenId` must exist.
             */
            function getApproved(uint256 tokenId) external view returns (address operator);
            /**
             * @dev Approve or remove `operator` as an operator for the caller.
             * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
             *
             * Requirements:
             *
             * - The `operator` cannot be the caller.
             *
             * Emits an {ApprovalForAll} event.
             */
            function setApprovalForAll(address operator, bool _approved) external;
            /**
             * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
             *
             * See {setApprovalForAll}
             */
            function isApprovedForAll(address owner, address operator) external view returns (bool);
            /**
              * @dev Safely transfers `tokenId` token from `from` to `to`.
              *
              * Requirements:
              *
              * - `from` cannot be the zero address.
              * - `to` cannot be the zero address.
              * - `tokenId` token must exist and be owned by `from`.
              * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
              * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
              *
              * Emits a {Transfer} event.
              */
            function safeTransferFrom(address from, address to, uint256 tokenId, bytes calldata data) external;
        }
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.7.0;
        /**
         * @dev Interface of the ERC165 standard, as defined in the
         * https://eips.ethereum.org/EIPS/eip-165[EIP].
         *
         * Implementers can declare support of contract interfaces, which can then be
         * queried by others ({ERC165Checker}).
         *
         * For an implementation, see {ERC165}.
         */
        interface IERC165Upgradeable {
            /**
             * @dev Returns true if this contract implements the interface defined by
             * `interfaceId`. See the corresponding
             * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
             * to learn more about how these ids are created.
             *
             * This function call must use less than 30 000 gas.
             */
            function supportsInterface(bytes4 interfaceId) external view returns (bool);
        }
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.7.0;
        /**
         * @dev Wrappers over Solidity's arithmetic operations with added overflow
         * checks.
         *
         * Arithmetic operations in Solidity wrap on overflow. This can easily result
         * in bugs, because programmers usually assume that an overflow raises an
         * error, which is the standard behavior in high level programming languages.
         * `SafeMath` restores this intuition by reverting the transaction when an
         * operation overflows.
         *
         * Using this library instead of the unchecked operations eliminates an entire
         * class of bugs, so it's recommended to use it always.
         */
        library SafeMathUpgradeable {
            /**
             * @dev Returns the addition of two unsigned integers, with an overflow flag.
             *
             * _Available since v3.4._
             */
            function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                uint256 c = a + b;
                if (c < a) return (false, 0);
                return (true, c);
            }
            /**
             * @dev Returns the substraction of two unsigned integers, with an overflow flag.
             *
             * _Available since v3.4._
             */
            function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                if (b > a) return (false, 0);
                return (true, a - b);
            }
            /**
             * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
             *
             * _Available since v3.4._
             */
            function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
                // benefit is lost if 'b' is also tested.
                // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
                if (a == 0) return (true, 0);
                uint256 c = a * b;
                if (c / a != b) return (false, 0);
                return (true, c);
            }
            /**
             * @dev Returns the division of two unsigned integers, with a division by zero flag.
             *
             * _Available since v3.4._
             */
            function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                if (b == 0) return (false, 0);
                return (true, a / b);
            }
            /**
             * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
             *
             * _Available since v3.4._
             */
            function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                if (b == 0) return (false, 0);
                return (true, a % b);
            }
            /**
             * @dev Returns the addition of two unsigned integers, reverting on
             * overflow.
             *
             * Counterpart to Solidity's `+` operator.
             *
             * Requirements:
             *
             * - Addition cannot overflow.
             */
            function add(uint256 a, uint256 b) internal pure returns (uint256) {
                uint256 c = a + b;
                require(c >= a, "SafeMath: addition overflow");
                return c;
            }
            /**
             * @dev Returns the subtraction of two unsigned integers, reverting on
             * overflow (when the result is negative).
             *
             * Counterpart to Solidity's `-` operator.
             *
             * Requirements:
             *
             * - Subtraction cannot overflow.
             */
            function sub(uint256 a, uint256 b) internal pure returns (uint256) {
                require(b <= a, "SafeMath: subtraction overflow");
                return a - b;
            }
            /**
             * @dev Returns the multiplication of two unsigned integers, reverting on
             * overflow.
             *
             * Counterpart to Solidity's `*` operator.
             *
             * Requirements:
             *
             * - Multiplication cannot overflow.
             */
            function mul(uint256 a, uint256 b) internal pure returns (uint256) {
                if (a == 0) return 0;
                uint256 c = a * b;
                require(c / a == b, "SafeMath: multiplication overflow");
                return c;
            }
            /**
             * @dev Returns the integer division of two unsigned integers, reverting on
             * division by zero. The result is rounded towards zero.
             *
             * Counterpart to Solidity's `/` operator. Note: this function uses a
             * `revert` opcode (which leaves remaining gas untouched) while Solidity
             * uses an invalid opcode to revert (consuming all remaining gas).
             *
             * Requirements:
             *
             * - The divisor cannot be zero.
             */
            function div(uint256 a, uint256 b) internal pure returns (uint256) {
                require(b > 0, "SafeMath: division by zero");
                return a / b;
            }
            /**
             * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
             * reverting when dividing by zero.
             *
             * Counterpart to Solidity's `%` operator. This function uses a `revert`
             * opcode (which leaves remaining gas untouched) while Solidity uses an
             * invalid opcode to revert (consuming all remaining gas).
             *
             * Requirements:
             *
             * - The divisor cannot be zero.
             */
            function mod(uint256 a, uint256 b) internal pure returns (uint256) {
                require(b > 0, "SafeMath: modulo by zero");
                return a % b;
            }
            /**
             * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
             * overflow (when the result is negative).
             *
             * CAUTION: This function is deprecated because it requires allocating memory for the error
             * message unnecessarily. For custom revert reasons use {trySub}.
             *
             * Counterpart to Solidity's `-` operator.
             *
             * Requirements:
             *
             * - Subtraction cannot overflow.
             */
            function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                require(b <= a, errorMessage);
                return a - b;
            }
            /**
             * @dev Returns the integer division of two unsigned integers, reverting with custom message on
             * division by zero. The result is rounded towards zero.
             *
             * CAUTION: This function is deprecated because it requires allocating memory for the error
             * message unnecessarily. For custom revert reasons use {tryDiv}.
             *
             * Counterpart to Solidity's `/` operator. Note: this function uses a
             * `revert` opcode (which leaves remaining gas untouched) while Solidity
             * uses an invalid opcode to revert (consuming all remaining gas).
             *
             * Requirements:
             *
             * - The divisor cannot be zero.
             */
            function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                require(b > 0, errorMessage);
                return a / b;
            }
            /**
             * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
             * reverting with custom message when dividing by zero.
             *
             * CAUTION: This function is deprecated because it requires allocating memory for the error
             * message unnecessarily. For custom revert reasons use {tryMod}.
             *
             * Counterpart to Solidity's `%` operator. This function uses a `revert`
             * opcode (which leaves remaining gas untouched) while Solidity uses an
             * invalid opcode to revert (consuming all remaining gas).
             *
             * Requirements:
             *
             * - The divisor cannot be zero.
             */
            function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                require(b > 0, errorMessage);
                return a % b;
            }
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        // solhint-disable
        pragma solidity ^0.7.0;
        interface IFNDNFT721 {
          function tokenCreator(uint256 tokenId) external view returns (address payable);
          function getTokenCreatorPaymentAddress(uint256 tokenId) external view returns (address payable);
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        /**
         * @dev Constant values shared across mixins.
         */
        abstract contract Constants {
          uint256 internal constant BASIS_POINTS = 10000;
        }
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.7.0;
        /**
         * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
         *
         * These functions can be used to verify that a message was signed by the holder
         * of the private keys of a given address.
         */
        library ECDSA {
            /**
             * @dev Returns the address that signed a hashed message (`hash`) with
             * `signature`. This address can then be used for verification purposes.
             *
             * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
             * this function rejects them by requiring the `s` value to be in the lower
             * half order, and the `v` value to be either 27 or 28.
             *
             * IMPORTANT: `hash` _must_ be the result of a hash operation for the
             * verification to be secure: it is possible to craft signatures that
             * recover to arbitrary addresses for non-hashed data. A safe way to ensure
             * this is by receiving a hash of the original message (which may otherwise
             * be too long), and then calling {toEthSignedMessageHash} on it.
             */
            function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
                // Check the signature length
                if (signature.length != 65) {
                    revert("ECDSA: invalid signature length");
                }
                // Divide the signature in r, s and v variables
                bytes32 r;
                bytes32 s;
                uint8 v;
                // ecrecover takes the signature parameters, and the only way to get them
                // currently is to use assembly.
                // solhint-disable-next-line no-inline-assembly
                assembly {
                    r := mload(add(signature, 0x20))
                    s := mload(add(signature, 0x40))
                    v := byte(0, mload(add(signature, 0x60)))
                }
                return recover(hash, v, r, s);
            }
            /**
             * @dev Overload of {ECDSA-recover-bytes32-bytes-} that receives the `v`,
             * `r` and `s` signature fields separately.
             */
            function recover(bytes32 hash, uint8 v, bytes32 r, bytes32 s) internal pure returns (address) {
                // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
                // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
                // the valid range for s in (281): 0 < s < secp256k1n ÷ 2 + 1, and for v in (282): v ∈ {27, 28}. Most
                // signatures from current libraries generate a unique signature with an s-value in the lower half order.
                //
                // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
                // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
                // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
                // these malleable signatures as well.
                require(uint256(s) <= 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0, "ECDSA: invalid signature 's' value");
                require(v == 27 || v == 28, "ECDSA: invalid signature 'v' value");
                // If the signature is valid (and not malleable), return the signer address
                address signer = ecrecover(hash, v, r, s);
                require(signer != address(0), "ECDSA: invalid signature");
                return signer;
            }
            /**
             * @dev Returns an Ethereum Signed Message, created from a `hash`. This
             * replicates the behavior of the
             * https://github.com/ethereum/wiki/wiki/JSON-RPC#eth_sign[`eth_sign`]
             * JSON-RPC method.
             *
             * See {recover}.
             */
            function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32) {
                // 32 is the length in bytes of hash,
                // enforced by the type signature above
                return keccak256(abi.encodePacked("\\x19Ethereum Signed Message:\
        32", hash));
            }
        }
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.7.0;
        /**
         * @dev Collection of functions related to the address type
         */
        library Address {
            /**
             * @dev Returns true if `account` is a contract.
             *
             * [IMPORTANT]
             * ====
             * It is unsafe to assume that an address for which this function returns
             * false is an externally-owned account (EOA) and not a contract.
             *
             * Among others, `isContract` will return false for the following
             * types of addresses:
             *
             *  - an externally-owned account
             *  - a contract in construction
             *  - an address where a contract will be created
             *  - an address where a contract lived, but was destroyed
             * ====
             */
            function isContract(address account) internal view returns (bool) {
                // This method relies on extcodesize, which returns 0 for contracts in
                // construction, since the code is only stored at the end of the
                // constructor execution.
                uint256 size;
                // solhint-disable-next-line no-inline-assembly
                assembly { size := extcodesize(account) }
                return size > 0;
            }
            /**
             * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
             * `recipient`, forwarding all available gas and reverting on errors.
             *
             * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
             * of certain opcodes, possibly making contracts go over the 2300 gas limit
             * imposed by `transfer`, making them unable to receive funds via
             * `transfer`. {sendValue} removes this limitation.
             *
             * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
             *
             * IMPORTANT: because control is transferred to `recipient`, care must be
             * taken to not create reentrancy vulnerabilities. Consider using
             * {ReentrancyGuard} or the
             * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
             */
            function sendValue(address payable recipient, uint256 amount) internal {
                require(address(this).balance >= amount, "Address: insufficient balance");
                // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
                (bool success, ) = recipient.call{ value: amount }("");
                require(success, "Address: unable to send value, recipient may have reverted");
            }
            /**
             * @dev Performs a Solidity function call using a low level `call`. A
             * plain`call` is an unsafe replacement for a function call: use this
             * function instead.
             *
             * If `target` reverts with a revert reason, it is bubbled up by this
             * function (like regular Solidity function calls).
             *
             * Returns the raw returned data. To convert to the expected return value,
             * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
             *
             * Requirements:
             *
             * - `target` must be a contract.
             * - calling `target` with `data` must not revert.
             *
             * _Available since v3.1._
             */
            function functionCall(address target, bytes memory data) internal returns (bytes memory) {
              return functionCall(target, data, "Address: low-level call failed");
            }
            /**
             * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
             * `errorMessage` as a fallback revert reason when `target` reverts.
             *
             * _Available since v3.1._
             */
            function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
                return functionCallWithValue(target, data, 0, errorMessage);
            }
            /**
             * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
             * but also transferring `value` wei to `target`.
             *
             * Requirements:
             *
             * - the calling contract must have an ETH balance of at least `value`.
             * - the called Solidity function must be `payable`.
             *
             * _Available since v3.1._
             */
            function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
                return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
            }
            /**
             * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
             * with `errorMessage` as a fallback revert reason when `target` reverts.
             *
             * _Available since v3.1._
             */
            function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
                require(address(this).balance >= value, "Address: insufficient balance for call");
                require(isContract(target), "Address: call to non-contract");
                // solhint-disable-next-line avoid-low-level-calls
                (bool success, bytes memory returndata) = target.call{ value: value }(data);
                return _verifyCallResult(success, returndata, errorMessage);
            }
            /**
             * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
             * but performing a static call.
             *
             * _Available since v3.3._
             */
            function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                return functionStaticCall(target, data, "Address: low-level static call failed");
            }
            /**
             * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
             * but performing a static call.
             *
             * _Available since v3.3._
             */
            function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
                require(isContract(target), "Address: static call to non-contract");
                // solhint-disable-next-line avoid-low-level-calls
                (bool success, bytes memory returndata) = target.staticcall(data);
                return _verifyCallResult(success, returndata, errorMessage);
            }
            /**
             * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
             * but performing a delegate call.
             *
             * _Available since v3.4._
             */
            function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
                return functionDelegateCall(target, data, "Address: low-level delegate call failed");
            }
            /**
             * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
             * but performing a delegate call.
             *
             * _Available since v3.4._
             */
            function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
                require(isContract(target), "Address: delegate call to non-contract");
                // solhint-disable-next-line avoid-low-level-calls
                (bool success, bytes memory returndata) = target.delegatecall(data);
                return _verifyCallResult(success, returndata, errorMessage);
            }
            function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
                if (success) {
                    return returndata;
                } else {
                    // Look for revert reason and bubble it up if present
                    if (returndata.length > 0) {
                        // The easiest way to bubble the revert reason is using memory via assembly
                        // solhint-disable-next-line no-inline-assembly
                        assembly {
                            let returndata_size := mload(returndata)
                            revert(add(32, returndata), returndata_size)
                        }
                    } else {
                        revert(errorMessage);
                    }
                }
            }
        }
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.7.0;
        /**
         * @dev String operations.
         */
        library Strings {
            /**
             * @dev Converts a `uint256` to its ASCII `string` representation.
             */
            function toString(uint256 value) internal pure returns (string memory) {
                // Inspired by OraclizeAPI's implementation - MIT licence
                // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol
                if (value == 0) {
                    return "0";
                }
                uint256 temp = value;
                uint256 digits;
                while (temp != 0) {
                    digits++;
                    temp /= 10;
                }
                bytes memory buffer = new bytes(digits);
                uint256 index = digits - 1;
                temp = value;
                while (temp != 0) {
                    buffer[index--] = bytes1(uint8(48 + temp % 10));
                    temp /= 10;
                }
                return string(buffer);
            }
        }
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.7.0;
        /**
         * @dev Interface of the ERC1271 standard signature validation method for
         * contracts as defined in https://eips.ethereum.org/EIPS/eip-1271[ERC-1271].
         *
         * from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v4.1.0/contracts/interfaces/IERC1271.sol
         */
        interface IERC1271 {
          /**
           * @dev Should return whether the signature provided is valid for the provided data
           * @param hash      Hash of the data to be signed
           * @param signature Signature byte array associated with _data
           */
          function isValidSignature(bytes32 hash, bytes memory signature) external view returns (bytes4 magicValue);
        }
        

        File 4 of 4: FNDNFT721
        /*
          ・
           * ★
              ・ 。
                 ・ ゚☆ 。
              * ★ ゚・。 *  。
                    * ☆ 。・゚*.。
                 ゚ *.。☆。★ ・
        ​
                              `                     .-:::::-.`              `-::---...```
                             `-:`               .:+ssssoooo++//:.`       .-/+shhhhhhhhhhhhhyyyssooo:
                            .--::.            .+ossso+/////++/:://-`   .////+shhhhhhhhhhhhhhhhhhhhhy
                          `-----::.         `/+////+++///+++/:--:/+/-  -////+shhhhhhhhhhhhhhhhhhhhhy
                         `------:::-`      `//-.``.-/+ooosso+:-.-/oso- -////+shhhhhhhhhhhhhhhhhhhhhy
                        .--------:::-`     :+:.`  .-/osyyyyyyso++syhyo.-////+shhhhhhhhhhhhhhhhhhhhhy
                      `-----------:::-.    +o+:-.-:/oyhhhhhhdhhhhhdddy:-////+shhhhhhhhhhhhhhhhhhhhhy
                     .------------::::--  `oys+/::/+shhhhhhhdddddddddy/-////+shhhhhhhhhhhhhhhhhhhhhy
                    .--------------:::::-` +ys+////+yhhhhhhhddddddddhy:-////+yhhhhhhhhhhhhhhhhhhhhhy
                  `----------------::::::-`.ss+/:::+oyhhhhhhhhhhhhhhho`-////+shhhhhhhhhhhhhhhhhhhhhy
                 .------------------:::::::.-so//::/+osyyyhhhhhhhhhys` -////+shhhhhhhhhhhhhhhhhhhhhy
               `.-------------------::/:::::..+o+////+oosssyyyyyyys+`  .////+shhhhhhhhhhhhhhhhhhhhhy
               .--------------------::/:::.`   -+o++++++oooosssss/.     `-//+shhhhhhhhhhhhhhhhhhhhyo
             .-------   ``````.......--`        `-/+ooooosso+/-`          `./++++///:::--...``hhhhyo
                                                      `````
           * 
              ・ 。
            ・  ゚☆ 。
              * ★ ゚・。 *  。
                    * ☆ 。・゚*.。
                 ゚ *.。☆。★ ・
            *  ゚。·*・。 ゚*
             ☆゚・。°*. ゚
          ・ ゚*。・゚★。
          ・ *゚。   *
         ・゚*。★・
         ☆∴。 *
        ・ 。
        */
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        import "@openzeppelin/contracts-upgradeable/introspection/ERC165Upgradeable.sol";
        import "./mixins/OZ/ERC721Upgradeable.sol";
        import "./mixins/FoundationTreasuryNode.sol";
        import "./mixins/roles/FoundationAdminRole.sol";
        import "./mixins/roles/FoundationOperatorRole.sol";
        import "./mixins/HasSecondarySaleFees.sol";
        import "./mixins/NFT721Core.sol";
        import "./mixins/NFT721Market.sol";
        import "./mixins/NFT721Creator.sol";
        import "./mixins/NFT721Metadata.sol";
        import "./mixins/NFT721Mint.sol";
        import "./mixins/AccountMigration.sol";
        import "./mixins/NFT721ProxyCall.sol";
        /**
         * @title Foundation NFTs implemented using the ERC-721 standard.
         * @dev This top level file holds no data directly to ease future upgrades.
         */
        contract FNDNFT721 is
          FoundationTreasuryNode,
          FoundationAdminRole,
          FoundationOperatorRole,
          AccountMigration,
          ERC165Upgradeable,
          HasSecondarySaleFees,
          ERC721Upgradeable,
          NFT721Core,
          NFT721ProxyCall,
          NFT721Creator,
          NFT721Market,
          NFT721Metadata,
          NFT721Mint
        {
          /**
           * @notice Called once to configure the contract after the initial deployment.
           * @dev This farms the initialize call out to inherited contracts as needed.
           */
          function initialize(
            address payable treasury,
            string memory name,
            string memory symbol
          ) public initializer {
            FoundationTreasuryNode._initializeFoundationTreasuryNode(treasury);
            ERC721Upgradeable.__ERC721_init(name, symbol);
            HasSecondarySaleFees._initializeHasSecondarySaleFees();
            NFT721Creator._initializeNFT721Creator();
            NFT721Mint._initializeNFT721Mint();
          }
          /**
           * @notice Allows a Foundation admin to update NFT config variables.
           * @dev This must be called right after the initial call to `initialize`.
           */
          function adminUpdateConfig(
            address _nftMarket,
            string memory baseURI,
            address proxyCallContract
          ) public onlyFoundationAdmin {
            _updateNFTMarket(_nftMarket);
            _updateBaseURI(baseURI);
            _updateProxyCall(proxyCallContract);
          }
          /**
           * @dev This is a no-op, just an explicit override to address compile errors due to inheritance.
           */
          function _burn(uint256 tokenId) internal override(ERC721Upgradeable, NFT721Creator, NFT721Metadata, NFT721Mint) {
            super._burn(tokenId);
          }
          function registerInterfaces() public virtual override(NFT721Mint, NFT721Creator, NFT721Market) {
            super.registerInterfaces();
          }
        }
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.7.0;
        import "./IERC165Upgradeable.sol";
        import "../proxy/Initializable.sol";
        /**
         * @dev Implementation of the {IERC165} interface.
         *
         * Contracts may inherit from this and call {_registerInterface} to declare
         * their support of an interface.
         */
        abstract contract ERC165Upgradeable is Initializable, IERC165Upgradeable {
            /*
             * bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7
             */
            bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;
            /**
             * @dev Mapping of interface ids to whether or not it's supported.
             */
            mapping(bytes4 => bool) private _supportedInterfaces;
            function __ERC165_init() internal initializer {
                __ERC165_init_unchained();
            }
            function __ERC165_init_unchained() internal initializer {
                // Derived contracts need only register support for their own interfaces,
                // we register support for ERC165 itself here
                _registerInterface(_INTERFACE_ID_ERC165);
            }
            /**
             * @dev See {IERC165-supportsInterface}.
             *
             * Time complexity O(1), guaranteed to always use less than 30 000 gas.
             */
            function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
                return _supportedInterfaces[interfaceId];
            }
            /**
             * @dev Registers the contract as an implementer of the interface defined by
             * `interfaceId`. Support of the actual ERC165 interface is automatic and
             * registering its interface id is not required.
             *
             * See {IERC165-supportsInterface}.
             *
             * Requirements:
             *
             * - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`).
             */
            function _registerInterface(bytes4 interfaceId) internal virtual {
                require(interfaceId != 0xffffffff, "ERC165: invalid interface id");
                _supportedInterfaces[interfaceId] = true;
            }
            uint256[49] private __gap;
        }
        // SPDX-License-Identifier: MIT
        // solhint-disable
        /**
         * Copied from the OpenZeppelin repository in order to make `_tokenURIs` internal instead of private.
         */
        pragma solidity >=0.6.0 <0.8.0;
        import "@openzeppelin/contracts-upgradeable/token/ERC721/IERC721Upgradeable.sol";
        import "@openzeppelin/contracts-upgradeable/token/ERC721/IERC721MetadataUpgradeable.sol";
        import "@openzeppelin/contracts-upgradeable/token/ERC721/IERC721EnumerableUpgradeable.sol";
        import "@openzeppelin/contracts-upgradeable/token/ERC721/IERC721ReceiverUpgradeable.sol";
        import "@openzeppelin/contracts-upgradeable/introspection/ERC165Upgradeable.sol";
        import "@openzeppelin/contracts-upgradeable/math/SafeMathUpgradeable.sol";
        import "@openzeppelin/contracts-upgradeable/utils/AddressUpgradeable.sol";
        import "@openzeppelin/contracts-upgradeable/utils/ContextUpgradeable.sol";
        import "@openzeppelin/contracts-upgradeable/utils/EnumerableSetUpgradeable.sol";
        import "@openzeppelin/contracts-upgradeable/utils/EnumerableMapUpgradeable.sol";
        import "@openzeppelin/contracts-upgradeable/utils/StringsUpgradeable.sol";
        import "@openzeppelin/contracts-upgradeable/proxy/Initializable.sol";
        /**
         * @title ERC721 Non-Fungible Token Standard basic implementation
         * @dev see https://eips.ethereum.org/EIPS/eip-721
         */
        contract ERC721Upgradeable is
          Initializable,
          ContextUpgradeable,
          ERC165Upgradeable,
          IERC721Upgradeable,
          IERC721MetadataUpgradeable,
          IERC721EnumerableUpgradeable
        {
          using SafeMathUpgradeable for uint256;
          using AddressUpgradeable for address;
          using EnumerableSetUpgradeable for EnumerableSetUpgradeable.UintSet;
          using EnumerableMapUpgradeable for EnumerableMapUpgradeable.UintToAddressMap;
          using StringsUpgradeable for uint256;
          // Equals to `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`
          // which can be also obtained as `IERC721Receiver(0).onERC721Received.selector`
          bytes4 private constant _ERC721_RECEIVED = 0x150b7a02;
          // Mapping from holder address to their (enumerable) set of owned tokens
          mapping(address => EnumerableSetUpgradeable.UintSet) private _holderTokens;
          // Enumerable mapping from token ids to their owners
          EnumerableMapUpgradeable.UintToAddressMap private _tokenOwners;
          // Mapping from token ID to approved address
          mapping(uint256 => address) private _tokenApprovals;
          // Mapping from owner to operator approvals
          mapping(address => mapping(address => bool)) private _operatorApprovals;
          // Token name
          string private _name;
          // Token symbol
          string private _symbol;
          // Optional mapping for token URIs
          mapping(uint256 => string) internal _tokenURIs;
          // Base URI
          string private _baseURI;
          /*
           *     bytes4(keccak256('balanceOf(address)')) == 0x70a08231
           *     bytes4(keccak256('ownerOf(uint256)')) == 0x6352211e
           *     bytes4(keccak256('approve(address,uint256)')) == 0x095ea7b3
           *     bytes4(keccak256('getApproved(uint256)')) == 0x081812fc
           *     bytes4(keccak256('setApprovalForAll(address,bool)')) == 0xa22cb465
           *     bytes4(keccak256('isApprovedForAll(address,address)')) == 0xe985e9c5
           *     bytes4(keccak256('transferFrom(address,address,uint256)')) == 0x23b872dd
           *     bytes4(keccak256('safeTransferFrom(address,address,uint256)')) == 0x42842e0e
           *     bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)')) == 0xb88d4fde
           *
           *     => 0x70a08231 ^ 0x6352211e ^ 0x095ea7b3 ^ 0x081812fc ^
           *        0xa22cb465 ^ 0xe985e9c5 ^ 0x23b872dd ^ 0x42842e0e ^ 0xb88d4fde == 0x80ac58cd
           */
          bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd;
          /*
           *     bytes4(keccak256('name()')) == 0x06fdde03
           *     bytes4(keccak256('symbol()')) == 0x95d89b41
           *     bytes4(keccak256('tokenURI(uint256)')) == 0xc87b56dd
           *
           *     => 0x06fdde03 ^ 0x95d89b41 ^ 0xc87b56dd == 0x5b5e139f
           */
          bytes4 private constant _INTERFACE_ID_ERC721_METADATA = 0x5b5e139f;
          /*
           *     bytes4(keccak256('totalSupply()')) == 0x18160ddd
           *     bytes4(keccak256('tokenOfOwnerByIndex(address,uint256)')) == 0x2f745c59
           *     bytes4(keccak256('tokenByIndex(uint256)')) == 0x4f6ccce7
           *
           *     => 0x18160ddd ^ 0x2f745c59 ^ 0x4f6ccce7 == 0x780e9d63
           */
          bytes4 private constant _INTERFACE_ID_ERC721_ENUMERABLE = 0x780e9d63;
          /**
           * @dev Initializes the contract by setting a `name` and a `symbol` to the token collection.
           */
          function __ERC721_init(string memory name_, string memory symbol_) internal initializer {
            __Context_init_unchained();
            __ERC165_init_unchained();
            __ERC721_init_unchained(name_, symbol_);
          }
          function __ERC721_init_unchained(string memory name_, string memory symbol_) internal initializer {
            _name = name_;
            _symbol = symbol_;
            // register the supported interfaces to conform to ERC721 via ERC165
            _registerInterface(_INTERFACE_ID_ERC721);
            _registerInterface(_INTERFACE_ID_ERC721_METADATA);
            _registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE);
          }
          /**
           * @dev See {IERC721-balanceOf}.
           */
          function balanceOf(address owner) public view override returns (uint256) {
            require(owner != address(0), "ERC721: balance query for the zero address");
            return _holderTokens[owner].length();
          }
          /**
           * @dev See {IERC721-ownerOf}.
           */
          function ownerOf(uint256 tokenId) public view override returns (address) {
            return _tokenOwners.get(tokenId, "ERC721: owner query for nonexistent token");
          }
          /**
           * @dev See {IERC721Metadata-name}.
           */
          function name() public view override returns (string memory) {
            return _name;
          }
          /**
           * @dev See {IERC721Metadata-symbol}.
           */
          function symbol() public view override returns (string memory) {
            return _symbol;
          }
          /**
           * @dev See {IERC721Metadata-tokenURI}.
           */
          function tokenURI(uint256 tokenId) public view override returns (string memory) {
            require(_exists(tokenId), "ERC721Metadata: URI query for nonexistent token");
            string memory _tokenURI = _tokenURIs[tokenId];
            // If there is no base URI, return the token URI.
            if (bytes(_baseURI).length == 0) {
              return _tokenURI;
            }
            // If both are set, concatenate the baseURI and tokenURI (via abi.encodePacked).
            if (bytes(_tokenURI).length > 0) {
              return string(abi.encodePacked(_baseURI, _tokenURI));
            }
            // If there is a baseURI but no tokenURI, concatenate the tokenID to the baseURI.
            return string(abi.encodePacked(_baseURI, tokenId.toString()));
          }
          /**
           * @dev Returns the base URI set via {_setBaseURI}. This will be
           * automatically added as a prefix in {tokenURI} to each token's URI, or
           * to the token ID if no specific URI is set for that token ID.
           */
          function baseURI() public view returns (string memory) {
            return _baseURI;
          }
          /**
           * @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.
           */
          function tokenOfOwnerByIndex(address owner, uint256 index) public view override returns (uint256) {
            return _holderTokens[owner].at(index);
          }
          /**
           * @dev See {IERC721Enumerable-totalSupply}.
           */
          function totalSupply() public view override returns (uint256) {
            // _tokenOwners are indexed by tokenIds, so .length() returns the number of tokenIds
            return _tokenOwners.length();
          }
          /**
           * @dev See {IERC721Enumerable-tokenByIndex}.
           */
          function tokenByIndex(uint256 index) public view override returns (uint256) {
            (uint256 tokenId, ) = _tokenOwners.at(index);
            return tokenId;
          }
          /**
           * @dev See {IERC721-approve}.
           */
          function approve(address to, uint256 tokenId) public virtual override {
            address owner = ownerOf(tokenId);
            require(to != owner, "ERC721: approval to current owner");
            require(
              _msgSender() == owner || isApprovedForAll(owner, _msgSender()),
              "ERC721: approve caller is not owner nor approved for all"
            );
            _approve(to, tokenId);
          }
          /**
           * @dev See {IERC721-getApproved}.
           */
          function getApproved(uint256 tokenId) public view override returns (address) {
            require(_exists(tokenId), "ERC721: approved query for nonexistent token");
            return _tokenApprovals[tokenId];
          }
          /**
           * @dev See {IERC721-setApprovalForAll}.
           */
          function setApprovalForAll(address operator, bool approved) public virtual override {
            require(operator != _msgSender(), "ERC721: approve to caller");
            _operatorApprovals[_msgSender()][operator] = approved;
            emit ApprovalForAll(_msgSender(), operator, approved);
          }
          /**
           * @dev See {IERC721-isApprovedForAll}.
           */
          function isApprovedForAll(address owner, address operator) public view override returns (bool) {
            return _operatorApprovals[owner][operator];
          }
          /**
           * @dev See {IERC721-transferFrom}.
           */
          function transferFrom(
            address from,
            address to,
            uint256 tokenId
          ) public virtual override {
            //solhint-disable-next-line max-line-length
            require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");
            _transfer(from, to, tokenId);
          }
          /**
           * @dev See {IERC721-safeTransferFrom}.
           */
          function safeTransferFrom(
            address from,
            address to,
            uint256 tokenId
          ) public virtual override {
            safeTransferFrom(from, to, tokenId, "");
          }
          /**
           * @dev See {IERC721-safeTransferFrom}.
           */
          function safeTransferFrom(
            address from,
            address to,
            uint256 tokenId,
            bytes memory _data
          ) public virtual override {
            require(_isApprovedOrOwner(_msgSender(), tokenId), "ERC721: transfer caller is not owner nor approved");
            _safeTransfer(from, to, tokenId, _data);
          }
          /**
           * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
           * are aware of the ERC721 protocol to prevent tokens from being forever locked.
           *
           * `_data` is additional data, it has no specified format and it is sent in call to `to`.
           *
           * This internal function is equivalent to {safeTransferFrom}, and can be used to e.g.
           * implement alternative mechanisms to perform token transfer, such as signature-based.
           *
           * Requirements:
           *
           * - `from` cannot be the zero address.
           * - `to` cannot be the zero address.
           * - `tokenId` token must exist and be owned by `from`.
           * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
           *
           * Emits a {Transfer} event.
           */
          function _safeTransfer(
            address from,
            address to,
            uint256 tokenId,
            bytes memory _data
          ) internal virtual {
            _transfer(from, to, tokenId);
            require(_checkOnERC721Received(from, to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer");
          }
          /**
           * @dev Returns whether `tokenId` exists.
           *
           * Tokens can be managed by their owner or approved accounts via {approve} or {setApprovalForAll}.
           *
           * Tokens start existing when they are minted (`_mint`),
           * and stop existing when they are burned (`_burn`).
           */
          function _exists(uint256 tokenId) internal view returns (bool) {
            return _tokenOwners.contains(tokenId);
          }
          /**
           * @dev Returns whether `spender` is allowed to manage `tokenId`.
           *
           * Requirements:
           *
           * - `tokenId` must exist.
           */
          function _isApprovedOrOwner(address spender, uint256 tokenId) internal view returns (bool) {
            require(_exists(tokenId), "ERC721: operator query for nonexistent token");
            address owner = ownerOf(tokenId);
            return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));
          }
          /**
             * @dev Safely mints `tokenId` and transfers it to `to`.
             *
             * Requirements:
             d*
             * - `tokenId` must not exist.
             * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
             *
             * Emits a {Transfer} event.
             */
          function _safeMint(address to, uint256 tokenId) internal virtual {
            _safeMint(to, tokenId, "");
          }
          /**
           * @dev Same as {xref-ERC721-_safeMint-address-uint256-}[`_safeMint`], with an additional `data` parameter which is
           * forwarded in {IERC721Receiver-onERC721Received} to contract recipients.
           */
          function _safeMint(
            address to,
            uint256 tokenId,
            bytes memory _data
          ) internal virtual {
            _mint(to, tokenId);
            require(
              _checkOnERC721Received(address(0), to, tokenId, _data),
              "ERC721: transfer to non ERC721Receiver implementer"
            );
          }
          /**
           * @dev Mints `tokenId` and transfers it to `to`.
           *
           * WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible
           *
           * Requirements:
           *
           * - `tokenId` must not exist.
           * - `to` cannot be the zero address.
           *
           * Emits a {Transfer} event.
           */
          function _mint(address to, uint256 tokenId) internal virtual {
            require(to != address(0), "ERC721: mint to the zero address");
            require(!_exists(tokenId), "ERC721: token already minted");
            _beforeTokenTransfer(address(0), to, tokenId);
            _holderTokens[to].add(tokenId);
            _tokenOwners.set(tokenId, to);
            emit Transfer(address(0), to, tokenId);
          }
          /**
           * @dev Destroys `tokenId`.
           * The approval is cleared when the token is burned.
           *
           * Requirements:
           *
           * - `tokenId` must exist.
           *
           * Emits a {Transfer} event.
           */
          function _burn(uint256 tokenId) internal virtual {
            address owner = ownerOf(tokenId);
            _beforeTokenTransfer(owner, address(0), tokenId);
            // Clear approvals
            _approve(address(0), tokenId);
            // Clear metadata (if any)
            if (bytes(_tokenURIs[tokenId]).length != 0) {
              delete _tokenURIs[tokenId];
            }
            _holderTokens[owner].remove(tokenId);
            _tokenOwners.remove(tokenId);
            emit Transfer(owner, address(0), tokenId);
          }
          /**
           * @dev Transfers `tokenId` from `from` to `to`.
           *  As opposed to {transferFrom}, this imposes no restrictions on msg.sender.
           *
           * Requirements:
           *
           * - `to` cannot be the zero address.
           * - `tokenId` token must be owned by `from`.
           *
           * Emits a {Transfer} event.
           */
          function _transfer(
            address from,
            address to,
            uint256 tokenId
          ) internal virtual {
            require(ownerOf(tokenId) == from, "ERC721: transfer of token that is not own");
            require(to != address(0), "ERC721: transfer to the zero address");
            _beforeTokenTransfer(from, to, tokenId);
            // Clear approvals from the previous owner
            _approve(address(0), tokenId);
            _holderTokens[from].remove(tokenId);
            _holderTokens[to].add(tokenId);
            _tokenOwners.set(tokenId, to);
            emit Transfer(from, to, tokenId);
          }
          /**
           * @dev Sets `_tokenURI` as the tokenURI of `tokenId`.
           *
           * Requirements:
           *
           * - `tokenId` must exist.
           */
          function _setTokenURI(uint256 tokenId, string memory _tokenURI) internal virtual {
            require(_exists(tokenId), "ERC721Metadata: URI set of nonexistent token");
            _tokenURIs[tokenId] = _tokenURI;
          }
          /**
           * @dev Internal function to set the base URI for all token IDs. It is
           * automatically added as a prefix to the value returned in {tokenURI},
           * or to the token ID if {tokenURI} is empty.
           */
          function _setBaseURI(string memory baseURI_) internal virtual {
            _baseURI = baseURI_;
          }
          /**
           * @dev Internal function to invoke {IERC721Receiver-onERC721Received} on a target address.
           * The call is not executed if the target address is not a contract.
           *
           * @param from address representing the previous owner of the given token ID
           * @param to target address that will receive the tokens
           * @param tokenId uint256 ID of the token to be transferred
           * @param _data bytes optional data to send along with the call
           * @return bool whether the call correctly returned the expected magic value
           */
          function _checkOnERC721Received(
            address from,
            address to,
            uint256 tokenId,
            bytes memory _data
          ) private returns (bool) {
            if (!to.isContract()) {
              return true;
            }
            bytes memory returndata = to.functionCall(
              abi.encodeWithSelector(
                IERC721ReceiverUpgradeable(to).onERC721Received.selector,
                _msgSender(),
                from,
                tokenId,
                _data
              ),
              "ERC721: transfer to non ERC721Receiver implementer"
            );
            bytes4 retval = abi.decode(returndata, (bytes4));
            return (retval == _ERC721_RECEIVED);
          }
          function _approve(address to, uint256 tokenId) private {
            _tokenApprovals[tokenId] = to;
            emit Approval(ownerOf(tokenId), to, tokenId);
          }
          /**
           * @dev Hook that is called before any token transfer. This includes minting
           * and burning.
           *
           * Calling conditions:
           *
           * - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be
           * transferred to `to`.
           * - When `from` is zero, `tokenId` will be minted for `to`.
           * - When `to` is zero, ``from``'s `tokenId` will be burned.
           * - `from` cannot be the zero address.
           * - `to` cannot be the zero address.
           *
           * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
           */
          function _beforeTokenTransfer(
            address from,
            address to,
            uint256 tokenId
          ) internal virtual {}
          uint256[41] private __gap;
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        import "@openzeppelin/contracts-upgradeable/proxy/Initializable.sol";
        import "@openzeppelin/contracts-upgradeable/utils/AddressUpgradeable.sol";
        /**
         * @notice A mixin that stores a reference to the Foundation treasury contract.
         */
        abstract contract FoundationTreasuryNode is Initializable {
          using AddressUpgradeable for address payable;
          address payable private treasury;
          /**
           * @dev Called once after the initial deployment to set the Foundation treasury address.
           */
          function _initializeFoundationTreasuryNode(address payable _treasury) internal initializer {
            require(_treasury.isContract(), "FoundationTreasuryNode: Address is not a contract");
            treasury = _treasury;
          }
          /**
           * @notice Returns the address of the Foundation treasury.
           */
          function getFoundationTreasury() public view returns (address payable) {
            return treasury;
          }
          // `______gap` is added to each mixin to allow adding new data slots or additional mixins in an upgrade-safe way.
          uint256[2000] private __gap;
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        import "../../interfaces/IAdminRole.sol";
        import "../FoundationTreasuryNode.sol";
        /**
         * @notice Allows a contract to leverage the admin role defined by the Foundation treasury.
         */
        abstract contract FoundationAdminRole is FoundationTreasuryNode {
          // This file uses 0 data slots (other than what's included via FoundationTreasuryNode)
          modifier onlyFoundationAdmin() {
            require(_isFoundationAdmin(), "FoundationAdminRole: caller does not have the Admin role");
            _;
          }
          function _isFoundationAdmin() internal view returns (bool) {
            return IAdminRole(getFoundationTreasury()).isAdmin(msg.sender);
          }
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        import "../../interfaces/IOperatorRole.sol";
        import "../FoundationTreasuryNode.sol";
        /**
         * @notice Allows a contract to leverage the operator role defined by the Foundation treasury.
         */
        abstract contract FoundationOperatorRole is FoundationTreasuryNode {
          // This file uses 0 data slots (other than what's included via FoundationTreasuryNode)
          function _isFoundationOperator() internal view returns (bool) {
            return IOperatorRole(getFoundationTreasury()).isOperator(msg.sender);
          }
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        import "@openzeppelin/contracts-upgradeable/introspection/ERC165Upgradeable.sol";
        import "@openzeppelin/contracts-upgradeable/proxy/Initializable.sol";
        /**
         * @notice An interface for communicating fees to 3rd party marketplaces.
         * @dev Originally implemented in mainnet contract 0x44d6e8933f8271abcf253c72f9ed7e0e4c0323b3
         */
        abstract contract HasSecondarySaleFees is Initializable, ERC165Upgradeable {
          /*
           * bytes4(keccak256('getFeeBps(uint256)')) == 0x0ebd4c7f
           * bytes4(keccak256('getFeeRecipients(uint256)')) == 0xb9c4d9fb
           *
           * => 0x0ebd4c7f ^ 0xb9c4d9fb == 0xb7799584
           */
          bytes4 private constant _INTERFACE_ID_FEES = 0xb7799584;
          /**
           * @dev Called once after the initial deployment to register the interface with ERC165.
           */
          function _initializeHasSecondarySaleFees() internal initializer {
            _registerInterface(_INTERFACE_ID_FEES);
          }
          function getFeeRecipients(uint256 id) public view virtual returns (address payable[] memory);
          function getFeeBps(uint256 id) public view virtual returns (uint256[] memory);
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        /**
         * @notice A place for common modifiers and functions used by various NFT721 mixins, if any.
         * @dev This also leaves a gap which can be used to add a new mixin to the top of the inheritance tree.
         */
        abstract contract NFT721Core {
          // 100 slots used when adding NFT721ProxyCall
          uint256[900] private ______gap;
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        import "@openzeppelin/contracts-upgradeable/utils/AddressUpgradeable.sol";
        import "../interfaces/IFNDNFTMarket.sol";
        import "./FoundationTreasuryNode.sol";
        import "./HasSecondarySaleFees.sol";
        import "./NFT721Creator.sol";
        /**
         * @notice Holds a reference to the Foundation Market and communicates fees to 3rd party marketplaces.
         */
        abstract contract NFT721Market is FoundationTreasuryNode, HasSecondarySaleFees, NFT721Creator {
          using AddressUpgradeable for address;
          event NFTMarketUpdated(address indexed nftMarket);
          IFNDNFTMarket private nftMarket;
          /**
           * @dev Get royalites of a token.  Returns list of receivers and basisPoints
           *
           *  bytes4(keccak256('getRoyalties(uint256)')) == 0xbb3bafd6
           */
          bytes4 private constant _INTERFACE_GET_ROYALTIES = 0xbb3bafd6;
          /**
           * @notice Allows ERC165 interfaces which were not included originally to be registered.
           */
          function registerInterfaces() public virtual override {
            super.registerInterfaces();
            _registerInterface(_INTERFACE_GET_ROYALTIES);
          }
          /**
           * @notice Returns the address of the Foundation NFTMarket contract.
           */
          function getNFTMarket() public view returns (address) {
            return address(nftMarket);
          }
          function _updateNFTMarket(address _nftMarket) internal {
            require(_nftMarket.isContract(), "NFT721Market: Market address is not a contract");
            nftMarket = IFNDNFTMarket(_nftMarket);
            emit NFTMarketUpdated(_nftMarket);
          }
          /**
           * @notice Returns an array of recipient addresses to which fees should be sent.
           * The expected fee amount is communicated with `getFeeBps`.
           */
          function getFeeRecipients(uint256 id) public view override returns (address payable[] memory) {
            require(_exists(id), "ERC721Metadata: Query for nonexistent token");
            address payable[] memory result = new address payable[](2);
            result[0] = getFoundationTreasury();
            result[1] = getTokenCreatorPaymentAddress(id);
            return result;
          }
          /**
           * @notice Returns an array of fees in basis points.
           * The expected recipients is communicated with `getFeeRecipients`.
           */
          function getFeeBps(
            uint256 /* id */
          ) public view override returns (uint256[] memory) {
            (, uint256 secondaryF8nFeeBasisPoints, uint256 secondaryCreatorFeeBasisPoints) = nftMarket.getFeeConfig();
            uint256[] memory result = new uint256[](2);
            result[0] = secondaryF8nFeeBasisPoints;
            result[1] = secondaryCreatorFeeBasisPoints;
            return result;
          }
          /**
           * @notice Get fee recipients and fees in a single call.
           * The data is the same as when calling getFeeRecipients and getFeeBps separately.
           */
          function getRoyalties(uint256 tokenId)
            public
            view
            returns (address payable[2] memory recipients, uint256[2] memory feesInBasisPoints)
          {
            require(_exists(tokenId), "ERC721Metadata: Query for nonexistent token");
            recipients[0] = getFoundationTreasury();
            recipients[1] = getTokenCreatorPaymentAddress(tokenId);
            (, uint256 secondaryF8nFeeBasisPoints, uint256 secondaryCreatorFeeBasisPoints) = nftMarket.getFeeConfig();
            feesInBasisPoints[0] = secondaryF8nFeeBasisPoints;
            feesInBasisPoints[1] = secondaryCreatorFeeBasisPoints;
          }
          uint256[1000] private ______gap;
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        import "@openzeppelin/contracts-upgradeable/proxy/Initializable.sol";
        import "./OZ/ERC721Upgradeable.sol";
        import "./AccountMigration.sol";
        import "../libraries/BytesLibrary.sol";
        import "./NFT721ProxyCall.sol";
        /**
         * @notice Allows each token to be associated with a creator.
         */
        abstract contract NFT721Creator is Initializable, AccountMigration, ERC721Upgradeable, NFT721ProxyCall {
          using BytesLibrary for bytes;
          mapping(uint256 => address payable) private tokenIdToCreator;
          /**
           * @dev Stores an optional alternate address to receive creator revenue and royalty payments.
           */
          mapping(uint256 => address payable) private tokenIdToCreatorPaymentAddress;
          event TokenCreatorUpdated(address indexed fromCreator, address indexed toCreator, uint256 indexed tokenId);
          event TokenCreatorPaymentAddressSet(
            address indexed fromPaymentAddress,
            address indexed toPaymentAddress,
            uint256 indexed tokenId
          );
          event NFTCreatorMigrated(uint256 indexed tokenId, address indexed originalAddress, address indexed newAddress);
          event NFTOwnerMigrated(uint256 indexed tokenId, address indexed originalAddress, address indexed newAddress);
          event PaymentAddressMigrated(
            uint256 indexed tokenId,
            address indexed originalAddress,
            address indexed newAddress,
            address originalPaymentAddress,
            address newPaymentAddress
          );
          /*
           * bytes4(keccak256('tokenCreator(uint256)')) == 0x40c1a064
           */
          bytes4 private constant _INTERFACE_TOKEN_CREATOR = 0x40c1a064;
          /*
           * bytes4(keccak256('getTokenCreatorPaymentAddress(uint256)')) == 0xec5f752e;
           */
          bytes4 private constant _INTERFACE_TOKEN_CREATOR_PAYMENT_ADDRESS = 0xec5f752e;
          modifier onlyCreatorAndOwner(uint256 tokenId) {
            require(tokenIdToCreator[tokenId] == msg.sender, "NFT721Creator: Caller is not creator");
            require(ownerOf(tokenId) == msg.sender, "NFT721Creator: Caller does not own the NFT");
            _;
          }
          /**
           * @dev Called once after the initial deployment to register the interface with ERC165.
           */
          function _initializeNFT721Creator() internal initializer {
            _registerInterface(_INTERFACE_TOKEN_CREATOR);
          }
          /**
           * @notice Allows ERC165 interfaces which were not included originally to be registered.
           */
          function registerInterfaces() public virtual {
            _registerInterface(_INTERFACE_TOKEN_CREATOR_PAYMENT_ADDRESS);
          }
          /**
           * @notice Returns the creator's address for a given tokenId.
           */
          function tokenCreator(uint256 tokenId) public view returns (address payable) {
            return tokenIdToCreator[tokenId];
          }
          /**
           * @notice Returns the payment address for a given tokenId.
           * @dev If an alternate address was not defined, the creator is returned instead.
           */
          function getTokenCreatorPaymentAddress(uint256 tokenId)
            public
            view
            returns (address payable tokenCreatorPaymentAddress)
          {
            tokenCreatorPaymentAddress = tokenIdToCreatorPaymentAddress[tokenId];
            if (tokenCreatorPaymentAddress == address(0)) {
              tokenCreatorPaymentAddress = tokenIdToCreator[tokenId];
            }
          }
          function _updateTokenCreator(uint256 tokenId, address payable creator) internal {
            emit TokenCreatorUpdated(tokenIdToCreator[tokenId], creator, tokenId);
            tokenIdToCreator[tokenId] = creator;
          }
          /**
           * @dev Allow setting a different address to send payments to for both primary sale revenue
           * and secondary sales royalties.
           */
          function _setTokenCreatorPaymentAddress(uint256 tokenId, address payable tokenCreatorPaymentAddress) internal {
            emit TokenCreatorPaymentAddressSet(tokenIdToCreatorPaymentAddress[tokenId], tokenCreatorPaymentAddress, tokenId);
            tokenIdToCreatorPaymentAddress[tokenId] = tokenCreatorPaymentAddress;
          }
          /**
           * @notice Allows the creator to burn if they currently own the NFT.
           */
          function burn(uint256 tokenId) public onlyCreatorAndOwner(tokenId) {
            _burn(tokenId);
          }
          /**
           * @notice Allows an NFT owner or creator and Foundation to work together in order to update the creator
           * to a new account and/or transfer NFTs to that account.
           * @param signature Message `I authorize Foundation to migrate my account to ${newAccount.address.toLowerCase()}`
           * signed by the original account.
           * @dev This will gracefully skip any NFTs that have been burned or transferred.
           */
          function adminAccountMigration(
            uint256[] calldata createdTokenIds,
            uint256[] calldata ownedTokenIds,
            address originalAddress,
            address payable newAddress,
            bytes calldata signature
          ) public onlyAuthorizedAccountMigration(originalAddress, newAddress, signature) {
            for (uint256 i = 0; i < ownedTokenIds.length; i++) {
              uint256 tokenId = ownedTokenIds[i];
              // Check that the token exists and still owned by the originalAddress
              // so that frontrunning a burn or transfer will not cause the entire tx to revert
              if (_exists(tokenId) && ownerOf(tokenId) == originalAddress) {
                _transfer(originalAddress, newAddress, tokenId);
                emit NFTOwnerMigrated(tokenId, originalAddress, newAddress);
              }
            }
            for (uint256 i = 0; i < createdTokenIds.length; i++) {
              uint256 tokenId = createdTokenIds[i];
              // The creator would be 0 if the token was burned before this call
              if (tokenIdToCreator[tokenId] != address(0)) {
                require(
                  tokenIdToCreator[tokenId] == originalAddress,
                  "NFT721Creator: Token was not created by the given address"
                );
                _updateTokenCreator(tokenId, newAddress);
                emit NFTCreatorMigrated(tokenId, originalAddress, newAddress);
              }
            }
          }
          /**
           * @notice Allows a split recipient and Foundation to work together in order to update the payment address
           * to a new account.
           * @param signature Message `I authorize Foundation to migrate my account to ${newAccount.address.toLowerCase()}`
           * signed by the original account.
           */
          function adminAccountMigrationForPaymentAddresses(
            uint256[] calldata paymentAddressTokenIds,
            address paymentAddressFactory,
            bytes memory paymentAddressCallData,
            uint256 addressLocationInCallData,
            address originalAddress,
            address payable newAddress,
            bytes calldata signature
          ) public onlyAuthorizedAccountMigration(originalAddress, newAddress, signature) {
            _adminAccountRecoveryForPaymentAddresses(
              paymentAddressTokenIds,
              paymentAddressFactory,
              paymentAddressCallData,
              addressLocationInCallData,
              originalAddress,
              newAddress
            );
          }
          /**
           * @dev Split into a second function to avoid stack too deep errors
           */
          function _adminAccountRecoveryForPaymentAddresses(
            uint256[] calldata paymentAddressTokenIds,
            address paymentAddressFactory,
            bytes memory paymentAddressCallData,
            uint256 addressLocationInCallData,
            address originalAddress,
            address payable newAddress
          ) private {
            // Call the factory and get the originalPaymentAddress
            address payable originalPaymentAddress = _proxyCallAndReturnContractAddress(
              paymentAddressFactory,
              paymentAddressCallData
            );
            // Confirm the original address and swap with the new address
            paymentAddressCallData.replaceAtIf(addressLocationInCallData, originalAddress, newAddress);
            // Call the factory and get the newPaymentAddress
            address payable newPaymentAddress = _proxyCallAndReturnContractAddress(
              paymentAddressFactory,
              paymentAddressCallData
            );
            // For each token, confirm the expected payment address and then update to the new one
            for (uint256 i = 0; i < paymentAddressTokenIds.length; i++) {
              uint256 tokenId = paymentAddressTokenIds[i];
              require(
                tokenIdToCreatorPaymentAddress[tokenId] == originalPaymentAddress,
                "NFT721Creator: Payment address is not the expected value"
              );
              _setTokenCreatorPaymentAddress(tokenId, newPaymentAddress);
              emit PaymentAddressMigrated(tokenId, originalAddress, newAddress, originalPaymentAddress, newPaymentAddress);
            }
          }
          /**
           * @dev Remove the creator record when burned.
           */
          function _burn(uint256 tokenId) internal virtual override {
            delete tokenIdToCreator[tokenId];
            super._burn(tokenId);
          }
          uint256[999] private ______gap;
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        import "@openzeppelin/contracts-upgradeable/utils/StringsUpgradeable.sol";
        import "./NFT721Core.sol";
        import "./NFT721Creator.sol";
        /**
         * @notice A mixin to extend the OpenZeppelin metadata implementation.
         */
        abstract contract NFT721Metadata is NFT721Creator {
          using StringsUpgradeable for uint256;
          /**
           * @dev Stores hashes minted by a creator to prevent duplicates.
           */
          mapping(address => mapping(string => bool)) private creatorToIPFSHashToMinted;
          event BaseURIUpdated(string baseURI);
          event TokenIPFSPathUpdated(uint256 indexed tokenId, string indexed indexedTokenIPFSPath, string tokenIPFSPath);
          // This event was used in an order version of the contract
          event NFTMetadataUpdated(string name, string symbol, string baseURI);
          /**
           * @notice Returns the IPFSPath to the metadata JSON file for a given NFT.
           */
          function getTokenIPFSPath(uint256 tokenId) public view returns (string memory) {
            return _tokenURIs[tokenId];
          }
          /**
           * @notice Checks if the creator has already minted a given NFT.
           */
          function getHasCreatorMintedIPFSHash(address creator, string memory tokenIPFSPath) public view returns (bool) {
            return creatorToIPFSHashToMinted[creator][tokenIPFSPath];
          }
          function _updateBaseURI(string memory _baseURI) internal {
            _setBaseURI(_baseURI);
            emit BaseURIUpdated(_baseURI);
          }
          /**
           * @dev The IPFS path should be the CID + file.extension, e.g.
           * `QmfPsfGwLhiJrU8t9HpG4wuyjgPo9bk8go4aQqSu9Qg4h7/metadata.json`
           */
          function _setTokenIPFSPath(uint256 tokenId, string memory _tokenIPFSPath) internal {
            // 46 is the minimum length for an IPFS content hash, it may be longer if paths are used
            require(bytes(_tokenIPFSPath).length >= 46, "NFT721Metadata: Invalid IPFS path");
            require(!creatorToIPFSHashToMinted[msg.sender][_tokenIPFSPath], "NFT721Metadata: NFT was already minted");
            creatorToIPFSHashToMinted[msg.sender][_tokenIPFSPath] = true;
            _setTokenURI(tokenId, _tokenIPFSPath);
          }
          /**
           * @dev When a token is burned, remove record of it allowing that creator to re-mint the same NFT again in the future.
           */
          function _burn(uint256 tokenId) internal virtual override {
            delete creatorToIPFSHashToMinted[msg.sender][_tokenURIs[tokenId]];
            super._burn(tokenId);
          }
          uint256[999] private ______gap;
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        import "./OZ/ERC721Upgradeable.sol";
        import "@openzeppelin/contracts-upgradeable/proxy/Initializable.sol";
        import "./NFT721Creator.sol";
        import "./NFT721Market.sol";
        import "./NFT721Metadata.sol";
        import "./NFT721ProxyCall.sol";
        /**
         * @notice Allows creators to mint NFTs.
         */
        abstract contract NFT721Mint is
          Initializable,
          ERC721Upgradeable,
          NFT721ProxyCall,
          NFT721Creator,
          NFT721Market,
          NFT721Metadata
        {
          uint256 private nextTokenId;
          event Minted(
            address indexed creator,
            uint256 indexed tokenId,
            string indexed indexedTokenIPFSPath,
            string tokenIPFSPath
          );
          /**
           * @notice Gets the tokenId of the next NFT minted.
           */
          function getNextTokenId() public view returns (uint256) {
            return nextTokenId;
          }
          /**
           * @dev Called once after the initial deployment to set the initial tokenId.
           */
          function _initializeNFT721Mint() internal initializer {
            // Use ID 1 for the first NFT tokenId
            nextTokenId = 1;
          }
          /**
           * @notice Allows a creator to mint an NFT.
           */
          function mint(string memory tokenIPFSPath) public returns (uint256 tokenId) {
            tokenId = nextTokenId++;
            _mint(msg.sender, tokenId);
            _updateTokenCreator(tokenId, msg.sender);
            _setTokenIPFSPath(tokenId, tokenIPFSPath);
            emit Minted(msg.sender, tokenId, tokenIPFSPath, tokenIPFSPath);
          }
          /**
           * @notice Allows a creator to mint an NFT and set approval for the Foundation marketplace.
           * This can be used by creators the first time they mint an NFT to save having to issue a separate
           * approval transaction before starting an auction.
           */
          function mintAndApproveMarket(string memory tokenIPFSPath) public returns (uint256 tokenId) {
            tokenId = mint(tokenIPFSPath);
            setApprovalForAll(getNFTMarket(), true);
          }
          /**
           * @notice Allows a creator to mint an NFT and have creator revenue/royalties sent to an alternate address.
           */
          function mintWithCreatorPaymentAddress(string memory tokenIPFSPath, address payable tokenCreatorPaymentAddress)
            public
            returns (uint256 tokenId)
          {
            require(tokenCreatorPaymentAddress != address(0), "NFT721Mint: tokenCreatorPaymentAddress is required");
            tokenId = mint(tokenIPFSPath);
            _setTokenCreatorPaymentAddress(tokenId, tokenCreatorPaymentAddress);
          }
          /**
           * @notice Allows a creator to mint an NFT and have creator revenue/royalties sent to an alternate address.
           * Also sets approval for the Foundation marketplace.  This can be used by creators the first time they mint an NFT to
           * save having to issue a separate approval transaction before starting an auction.
           */
          function mintWithCreatorPaymentAddressAndApproveMarket(
            string memory tokenIPFSPath,
            address payable tokenCreatorPaymentAddress
          ) public returns (uint256 tokenId) {
            tokenId = mintWithCreatorPaymentAddress(tokenIPFSPath, tokenCreatorPaymentAddress);
            setApprovalForAll(getNFTMarket(), true);
          }
          /**
           * @notice Allows a creator to mint an NFT and have creator revenue/royalties sent to an alternate address
           * which is defined by a contract call, typically a proxy contract address representing the payment terms.
           */
          function mintWithCreatorPaymentFactory(
            string memory tokenIPFSPath,
            address paymentAddressFactory,
            bytes memory paymentAddressCallData
          ) public returns (uint256 tokenId) {
            address payable tokenCreatorPaymentAddress = _proxyCallAndReturnContractAddress(
              paymentAddressFactory,
              paymentAddressCallData
            );
            tokenId = mintWithCreatorPaymentAddress(tokenIPFSPath, tokenCreatorPaymentAddress);
          }
          /**
           * @notice Allows a creator to mint an NFT and have creator revenue/royalties sent to an alternate address
           * which is defined by a contract call, typically a proxy contract address representing the payment terms.
           * Also sets approval for the Foundation marketplace.  This can be used by creators the first time they mint an NFT to
           * save having to issue a separate approval transaction before starting an auction.
           */
          function mintWithCreatorPaymentFactoryAndApproveMarket(
            string memory tokenIPFSPath,
            address paymentAddressFactory,
            bytes memory paymentAddressCallData
          ) public returns (uint256 tokenId) {
            tokenId = mintWithCreatorPaymentFactory(tokenIPFSPath, paymentAddressFactory, paymentAddressCallData);
            setApprovalForAll(getNFTMarket(), true);
          }
          /**
           * @dev Explicit override to address compile errors.
           */
          function _burn(uint256 tokenId) internal virtual override(ERC721Upgradeable, NFT721Creator, NFT721Metadata) {
            super._burn(tokenId);
          }
          function registerInterfaces() public virtual override(NFT721Creator, NFT721Market) {
            super.registerInterfaces();
          }
          uint256[1000] private ______gap;
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        import "@openzeppelin/contracts/cryptography/ECDSA.sol";
        import "@openzeppelin/contracts/utils/Address.sol";
        import "@openzeppelin/contracts/utils/Strings.sol";
        import "./roles/FoundationOperatorRole.sol";
        import "../interfaces/IERC1271.sol";
        /**
         * @notice Checks for a valid signature authorizing the migration of an account to a new address.
         * @dev This is shared by both the FNDNFT721 and FNDNFTMarket, and the same signature authorizes both.
         */
        abstract contract AccountMigration is FoundationOperatorRole {
          // From https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v4.1.0/contracts/utils/cryptography
          function _isValidSignatureNow(
            address signer,
            bytes32 hash,
            bytes memory signature
          ) private view returns (bool) {
            if (Address.isContract(signer)) {
              try IERC1271(signer).isValidSignature(hash, signature) returns (bytes4 magicValue) {
                return magicValue == IERC1271(signer).isValidSignature.selector;
              } catch {
                return false;
              }
            } else {
              return ECDSA.recover(hash, signature) == signer;
            }
          }
          // From https://ethereum.stackexchange.com/questions/8346/convert-address-to-string
          function _toAsciiString(address x) private pure returns (string memory) {
            bytes memory s = new bytes(42);
            s[0] = "0";
            s[1] = "x";
            for (uint256 i = 0; i < 20; i++) {
              bytes1 b = bytes1(uint8(uint256(uint160(x)) / (2**(8 * (19 - i)))));
              bytes1 hi = bytes1(uint8(b) / 16);
              bytes1 lo = bytes1(uint8(b) - 16 * uint8(hi));
              s[2 * i + 2] = _char(hi);
              s[2 * i + 3] = _char(lo);
            }
            return string(s);
          }
          function _char(bytes1 b) private pure returns (bytes1 c) {
            if (uint8(b) < 10) return bytes1(uint8(b) + 0x30);
            else return bytes1(uint8(b) + 0x57);
          }
          // From https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v4.1.0/contracts/utils/cryptography/ECDSA.sol
          // Modified to accept messages (instead of the message hash)
          function _toEthSignedMessage(bytes memory message) private pure returns (bytes32) {
            return keccak256(abi.encodePacked("\\x19Ethereum Signed Message:\
        ", Strings.toString(message.length), message));
          }
          /**
           * @dev Confirms the msg.sender is a Foundation operator and that the signature provided is valid.
           * @param signature Message `I authorize Foundation to migrate my account to ${newAccount.address.toLowerCase()}`
           * signed by the original account.
           */
          modifier onlyAuthorizedAccountMigration(
            address originalAddress,
            address newAddress,
            bytes memory signature
          ) {
            require(_isFoundationOperator(), "AccountMigration: Caller is not an operator");
            require(originalAddress != newAddress, "AccountMigration: Cannot migrate to the same account");
            bytes32 hash = _toEthSignedMessage(
              abi.encodePacked("I authorize Foundation to migrate my account to ", _toAsciiString(newAddress))
            );
            require(
              _isValidSignatureNow(originalAddress, hash, signature),
              "AccountMigration: Signature must be from the original account"
            );
            _;
          }
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        import "@openzeppelin/contracts-upgradeable/utils/AddressUpgradeable.sol";
        import "../interfaces/IProxyCall.sol";
        /**
         * @notice Forwards arbitrary calls to an external contract to be processed.
         * @dev This is used so that the from address of the calling contract does not have
         * any special permissions (e.g. ERC-20 transfer).
         */
        abstract contract NFT721ProxyCall {
          using AddressUpgradeable for address payable;
          IProxyCall private proxyCall;
          event ProxyCallContractUpdated(address indexed proxyCallContract);
          /**
           * @dev Called by the adminUpdateConfig function to set the address of the proxy call contract.
           */
          function _updateProxyCall(address proxyCallContract) internal {
            proxyCall = IProxyCall(proxyCallContract);
            emit ProxyCallContractUpdated(proxyCallContract);
          }
          /**
           * @notice Returns the address of the current proxy call contract.
           */
          function proxyCallAddress() external view returns (address) {
            return address(proxyCall);
          }
          /**
           * @dev Used by other mixins to make external calls through the proxy contract.
           * This will fail if the proxyCall address is address(0).
           */
          function _proxyCallAndReturnContractAddress(address externalContract, bytes memory callData)
            internal
            returns (address payable result)
          {
            result = proxyCall.proxyCallAndReturnAddress(externalContract, callData);
            require(result.isContract(), "NFT721ProxyCall: address returned is not a contract");
          }
          // This mixin uses a total of 100 slots
          uint256[99] private ______gap;
        }
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.7.0;
        /**
         * @dev Interface of the ERC165 standard, as defined in the
         * https://eips.ethereum.org/EIPS/eip-165[EIP].
         *
         * Implementers can declare support of contract interfaces, which can then be
         * queried by others ({ERC165Checker}).
         *
         * For an implementation, see {ERC165}.
         */
        interface IERC165Upgradeable {
            /**
             * @dev Returns true if this contract implements the interface defined by
             * `interfaceId`. See the corresponding
             * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
             * to learn more about how these ids are created.
             *
             * This function call must use less than 30 000 gas.
             */
            function supportsInterface(bytes4 interfaceId) external view returns (bool);
        }
        // SPDX-License-Identifier: MIT
        // solhint-disable-next-line compiler-version
        pragma solidity >=0.4.24 <0.8.0;
        import "../utils/AddressUpgradeable.sol";
        /**
         * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
         * behind a proxy. Since a proxied contract can't have a constructor, it's common to move constructor logic to an
         * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
         * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
         *
         * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
         * possible by providing the encoded function call as the `_data` argument to {UpgradeableProxy-constructor}.
         *
         * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
         * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
         */
        abstract contract Initializable {
            /**
             * @dev Indicates that the contract has been initialized.
             */
            bool private _initialized;
            /**
             * @dev Indicates that the contract is in the process of being initialized.
             */
            bool private _initializing;
            /**
             * @dev Modifier to protect an initializer function from being invoked twice.
             */
            modifier initializer() {
                require(_initializing || _isConstructor() || !_initialized, "Initializable: contract is already initialized");
                bool isTopLevelCall = !_initializing;
                if (isTopLevelCall) {
                    _initializing = true;
                    _initialized = true;
                }
                _;
                if (isTopLevelCall) {
                    _initializing = false;
                }
            }
            /// @dev Returns true if and only if the function is running in the constructor
            function _isConstructor() private view returns (bool) {
                return !AddressUpgradeable.isContract(address(this));
            }
        }
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.7.0;
        /**
         * @dev Collection of functions related to the address type
         */
        library AddressUpgradeable {
            /**
             * @dev Returns true if `account` is a contract.
             *
             * [IMPORTANT]
             * ====
             * It is unsafe to assume that an address for which this function returns
             * false is an externally-owned account (EOA) and not a contract.
             *
             * Among others, `isContract` will return false for the following
             * types of addresses:
             *
             *  - an externally-owned account
             *  - a contract in construction
             *  - an address where a contract will be created
             *  - an address where a contract lived, but was destroyed
             * ====
             */
            function isContract(address account) internal view returns (bool) {
                // This method relies on extcodesize, which returns 0 for contracts in
                // construction, since the code is only stored at the end of the
                // constructor execution.
                uint256 size;
                // solhint-disable-next-line no-inline-assembly
                assembly { size := extcodesize(account) }
                return size > 0;
            }
            /**
             * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
             * `recipient`, forwarding all available gas and reverting on errors.
             *
             * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
             * of certain opcodes, possibly making contracts go over the 2300 gas limit
             * imposed by `transfer`, making them unable to receive funds via
             * `transfer`. {sendValue} removes this limitation.
             *
             * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
             *
             * IMPORTANT: because control is transferred to `recipient`, care must be
             * taken to not create reentrancy vulnerabilities. Consider using
             * {ReentrancyGuard} or the
             * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
             */
            function sendValue(address payable recipient, uint256 amount) internal {
                require(address(this).balance >= amount, "Address: insufficient balance");
                // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
                (bool success, ) = recipient.call{ value: amount }("");
                require(success, "Address: unable to send value, recipient may have reverted");
            }
            /**
             * @dev Performs a Solidity function call using a low level `call`. A
             * plain`call` is an unsafe replacement for a function call: use this
             * function instead.
             *
             * If `target` reverts with a revert reason, it is bubbled up by this
             * function (like regular Solidity function calls).
             *
             * Returns the raw returned data. To convert to the expected return value,
             * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
             *
             * Requirements:
             *
             * - `target` must be a contract.
             * - calling `target` with `data` must not revert.
             *
             * _Available since v3.1._
             */
            function functionCall(address target, bytes memory data) internal returns (bytes memory) {
              return functionCall(target, data, "Address: low-level call failed");
            }
            /**
             * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
             * `errorMessage` as a fallback revert reason when `target` reverts.
             *
             * _Available since v3.1._
             */
            function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
                return functionCallWithValue(target, data, 0, errorMessage);
            }
            /**
             * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
             * but also transferring `value` wei to `target`.
             *
             * Requirements:
             *
             * - the calling contract must have an ETH balance of at least `value`.
             * - the called Solidity function must be `payable`.
             *
             * _Available since v3.1._
             */
            function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
                return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
            }
            /**
             * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
             * with `errorMessage` as a fallback revert reason when `target` reverts.
             *
             * _Available since v3.1._
             */
            function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
                require(address(this).balance >= value, "Address: insufficient balance for call");
                require(isContract(target), "Address: call to non-contract");
                // solhint-disable-next-line avoid-low-level-calls
                (bool success, bytes memory returndata) = target.call{ value: value }(data);
                return _verifyCallResult(success, returndata, errorMessage);
            }
            /**
             * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
             * but performing a static call.
             *
             * _Available since v3.3._
             */
            function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                return functionStaticCall(target, data, "Address: low-level static call failed");
            }
            /**
             * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
             * but performing a static call.
             *
             * _Available since v3.3._
             */
            function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
                require(isContract(target), "Address: static call to non-contract");
                // solhint-disable-next-line avoid-low-level-calls
                (bool success, bytes memory returndata) = target.staticcall(data);
                return _verifyCallResult(success, returndata, errorMessage);
            }
            function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
                if (success) {
                    return returndata;
                } else {
                    // Look for revert reason and bubble it up if present
                    if (returndata.length > 0) {
                        // The easiest way to bubble the revert reason is using memory via assembly
                        // solhint-disable-next-line no-inline-assembly
                        assembly {
                            let returndata_size := mload(returndata)
                            revert(add(32, returndata), returndata_size)
                        }
                    } else {
                        revert(errorMessage);
                    }
                }
            }
        }
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.7.0;
        import "../../introspection/IERC165Upgradeable.sol";
        /**
         * @dev Required interface of an ERC721 compliant contract.
         */
        interface IERC721Upgradeable is IERC165Upgradeable {
            /**
             * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
             */
            event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
            /**
             * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
             */
            event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
            /**
             * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
             */
            event ApprovalForAll(address indexed owner, address indexed operator, bool approved);
            /**
             * @dev Returns the number of tokens in ``owner``'s account.
             */
            function balanceOf(address owner) external view returns (uint256 balance);
            /**
             * @dev Returns the owner of the `tokenId` token.
             *
             * Requirements:
             *
             * - `tokenId` must exist.
             */
            function ownerOf(uint256 tokenId) external view returns (address owner);
            /**
             * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
             * are aware of the ERC721 protocol to prevent tokens from being forever locked.
             *
             * Requirements:
             *
             * - `from` cannot be the zero address.
             * - `to` cannot be the zero address.
             * - `tokenId` token must exist and be owned by `from`.
             * - If the caller is not `from`, it must be have been allowed to move this token by either {approve} or {setApprovalForAll}.
             * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
             *
             * Emits a {Transfer} event.
             */
            function safeTransferFrom(address from, address to, uint256 tokenId) external;
            /**
             * @dev Transfers `tokenId` token from `from` to `to`.
             *
             * WARNING: Usage of this method is discouraged, use {safeTransferFrom} whenever possible.
             *
             * Requirements:
             *
             * - `from` cannot be the zero address.
             * - `to` cannot be the zero address.
             * - `tokenId` token must be owned by `from`.
             * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
             *
             * Emits a {Transfer} event.
             */
            function transferFrom(address from, address to, uint256 tokenId) external;
            /**
             * @dev Gives permission to `to` to transfer `tokenId` token to another account.
             * The approval is cleared when the token is transferred.
             *
             * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
             *
             * Requirements:
             *
             * - The caller must own the token or be an approved operator.
             * - `tokenId` must exist.
             *
             * Emits an {Approval} event.
             */
            function approve(address to, uint256 tokenId) external;
            /**
             * @dev Returns the account approved for `tokenId` token.
             *
             * Requirements:
             *
             * - `tokenId` must exist.
             */
            function getApproved(uint256 tokenId) external view returns (address operator);
            /**
             * @dev Approve or remove `operator` as an operator for the caller.
             * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
             *
             * Requirements:
             *
             * - The `operator` cannot be the caller.
             *
             * Emits an {ApprovalForAll} event.
             */
            function setApprovalForAll(address operator, bool _approved) external;
            /**
             * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
             *
             * See {setApprovalForAll}
             */
            function isApprovedForAll(address owner, address operator) external view returns (bool);
            /**
              * @dev Safely transfers `tokenId` token from `from` to `to`.
              *
              * Requirements:
              *
              * - `from` cannot be the zero address.
              * - `to` cannot be the zero address.
              * - `tokenId` token must exist and be owned by `from`.
              * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
              * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
              *
              * Emits a {Transfer} event.
              */
            function safeTransferFrom(address from, address to, uint256 tokenId, bytes calldata data) external;
        }
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.7.0;
        import "./IERC721Upgradeable.sol";
        /**
         * @title ERC-721 Non-Fungible Token Standard, optional metadata extension
         * @dev See https://eips.ethereum.org/EIPS/eip-721
         */
        interface IERC721MetadataUpgradeable is IERC721Upgradeable {
            /**
             * @dev Returns the token collection name.
             */
            function name() external view returns (string memory);
            /**
             * @dev Returns the token collection symbol.
             */
            function symbol() external view returns (string memory);
            /**
             * @dev Returns the Uniform Resource Identifier (URI) for `tokenId` token.
             */
            function tokenURI(uint256 tokenId) external view returns (string memory);
        }
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.7.0;
        import "./IERC721Upgradeable.sol";
        /**
         * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
         * @dev See https://eips.ethereum.org/EIPS/eip-721
         */
        interface IERC721EnumerableUpgradeable is IERC721Upgradeable {
            /**
             * @dev Returns the total amount of tokens stored by the contract.
             */
            function totalSupply() external view returns (uint256);
            /**
             * @dev Returns a token ID owned by `owner` at a given `index` of its token list.
             * Use along with {balanceOf} to enumerate all of ``owner``'s tokens.
             */
            function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256 tokenId);
            /**
             * @dev Returns a token ID at a given `index` of all the tokens stored by the contract.
             * Use along with {totalSupply} to enumerate all tokens.
             */
            function tokenByIndex(uint256 index) external view returns (uint256);
        }
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.7.0;
        /**
         * @title ERC721 token receiver interface
         * @dev Interface for any contract that wants to support safeTransfers
         * from ERC721 asset contracts.
         */
        interface IERC721ReceiverUpgradeable {
            /**
             * @dev Whenever an {IERC721} `tokenId` token is transferred to this contract via {IERC721-safeTransferFrom}
             * by `operator` from `from`, this function is called.
             *
             * It must return its Solidity selector to confirm the token transfer.
             * If any other value is returned or the interface is not implemented by the recipient, the transfer will be reverted.
             *
             * The selector can be obtained in Solidity with `IERC721.onERC721Received.selector`.
             */
            function onERC721Received(address operator, address from, uint256 tokenId, bytes calldata data) external returns (bytes4);
        }
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.7.0;
        /**
         * @dev Wrappers over Solidity's arithmetic operations with added overflow
         * checks.
         *
         * Arithmetic operations in Solidity wrap on overflow. This can easily result
         * in bugs, because programmers usually assume that an overflow raises an
         * error, which is the standard behavior in high level programming languages.
         * `SafeMath` restores this intuition by reverting the transaction when an
         * operation overflows.
         *
         * Using this library instead of the unchecked operations eliminates an entire
         * class of bugs, so it's recommended to use it always.
         */
        library SafeMathUpgradeable {
            /**
             * @dev Returns the addition of two unsigned integers, with an overflow flag.
             *
             * _Available since v3.4._
             */
            function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                uint256 c = a + b;
                if (c < a) return (false, 0);
                return (true, c);
            }
            /**
             * @dev Returns the substraction of two unsigned integers, with an overflow flag.
             *
             * _Available since v3.4._
             */
            function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                if (b > a) return (false, 0);
                return (true, a - b);
            }
            /**
             * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
             *
             * _Available since v3.4._
             */
            function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
                // benefit is lost if 'b' is also tested.
                // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
                if (a == 0) return (true, 0);
                uint256 c = a * b;
                if (c / a != b) return (false, 0);
                return (true, c);
            }
            /**
             * @dev Returns the division of two unsigned integers, with a division by zero flag.
             *
             * _Available since v3.4._
             */
            function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                if (b == 0) return (false, 0);
                return (true, a / b);
            }
            /**
             * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
             *
             * _Available since v3.4._
             */
            function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
                if (b == 0) return (false, 0);
                return (true, a % b);
            }
            /**
             * @dev Returns the addition of two unsigned integers, reverting on
             * overflow.
             *
             * Counterpart to Solidity's `+` operator.
             *
             * Requirements:
             *
             * - Addition cannot overflow.
             */
            function add(uint256 a, uint256 b) internal pure returns (uint256) {
                uint256 c = a + b;
                require(c >= a, "SafeMath: addition overflow");
                return c;
            }
            /**
             * @dev Returns the subtraction of two unsigned integers, reverting on
             * overflow (when the result is negative).
             *
             * Counterpart to Solidity's `-` operator.
             *
             * Requirements:
             *
             * - Subtraction cannot overflow.
             */
            function sub(uint256 a, uint256 b) internal pure returns (uint256) {
                require(b <= a, "SafeMath: subtraction overflow");
                return a - b;
            }
            /**
             * @dev Returns the multiplication of two unsigned integers, reverting on
             * overflow.
             *
             * Counterpart to Solidity's `*` operator.
             *
             * Requirements:
             *
             * - Multiplication cannot overflow.
             */
            function mul(uint256 a, uint256 b) internal pure returns (uint256) {
                if (a == 0) return 0;
                uint256 c = a * b;
                require(c / a == b, "SafeMath: multiplication overflow");
                return c;
            }
            /**
             * @dev Returns the integer division of two unsigned integers, reverting on
             * division by zero. The result is rounded towards zero.
             *
             * Counterpart to Solidity's `/` operator. Note: this function uses a
             * `revert` opcode (which leaves remaining gas untouched) while Solidity
             * uses an invalid opcode to revert (consuming all remaining gas).
             *
             * Requirements:
             *
             * - The divisor cannot be zero.
             */
            function div(uint256 a, uint256 b) internal pure returns (uint256) {
                require(b > 0, "SafeMath: division by zero");
                return a / b;
            }
            /**
             * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
             * reverting when dividing by zero.
             *
             * Counterpart to Solidity's `%` operator. This function uses a `revert`
             * opcode (which leaves remaining gas untouched) while Solidity uses an
             * invalid opcode to revert (consuming all remaining gas).
             *
             * Requirements:
             *
             * - The divisor cannot be zero.
             */
            function mod(uint256 a, uint256 b) internal pure returns (uint256) {
                require(b > 0, "SafeMath: modulo by zero");
                return a % b;
            }
            /**
             * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
             * overflow (when the result is negative).
             *
             * CAUTION: This function is deprecated because it requires allocating memory for the error
             * message unnecessarily. For custom revert reasons use {trySub}.
             *
             * Counterpart to Solidity's `-` operator.
             *
             * Requirements:
             *
             * - Subtraction cannot overflow.
             */
            function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                require(b <= a, errorMessage);
                return a - b;
            }
            /**
             * @dev Returns the integer division of two unsigned integers, reverting with custom message on
             * division by zero. The result is rounded towards zero.
             *
             * CAUTION: This function is deprecated because it requires allocating memory for the error
             * message unnecessarily. For custom revert reasons use {tryDiv}.
             *
             * Counterpart to Solidity's `/` operator. Note: this function uses a
             * `revert` opcode (which leaves remaining gas untouched) while Solidity
             * uses an invalid opcode to revert (consuming all remaining gas).
             *
             * Requirements:
             *
             * - The divisor cannot be zero.
             */
            function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                require(b > 0, errorMessage);
                return a / b;
            }
            /**
             * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
             * reverting with custom message when dividing by zero.
             *
             * CAUTION: This function is deprecated because it requires allocating memory for the error
             * message unnecessarily. For custom revert reasons use {tryMod}.
             *
             * Counterpart to Solidity's `%` operator. This function uses a `revert`
             * opcode (which leaves remaining gas untouched) while Solidity uses an
             * invalid opcode to revert (consuming all remaining gas).
             *
             * Requirements:
             *
             * - The divisor cannot be zero.
             */
            function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
                require(b > 0, errorMessage);
                return a % b;
            }
        }
        // SPDX-License-Identifier: MIT
        pragma solidity >=0.6.0 <0.8.0;
        import "../proxy/Initializable.sol";
        /*
         * @dev Provides information about the current execution context, including the
         * sender of the transaction and its data. While these are generally available
         * via msg.sender and msg.data, they should not be accessed in such a direct
         * manner, since when dealing with GSN meta-transactions the account sending and
         * paying for execution may not be the actual sender (as far as an application
         * is concerned).
         *
         * This contract is only required for intermediate, library-like contracts.
         */
        abstract contract ContextUpgradeable is Initializable {
            function __Context_init() internal initializer {
                __Context_init_unchained();
            }
            function __Context_init_unchained() internal initializer {
            }
            function _msgSender() internal view virtual returns (address payable) {
                return msg.sender;
            }
            function _msgData() internal view virtual returns (bytes memory) {
                this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
                return msg.data;
            }
            uint256[50] private __gap;
        }
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.7.0;
        /**
         * @dev Library for managing
         * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
         * types.
         *
         * Sets have the following properties:
         *
         * - Elements are added, removed, and checked for existence in constant time
         * (O(1)).
         * - Elements are enumerated in O(n). No guarantees are made on the ordering.
         *
         * ```
         * contract Example {
         *     // Add the library methods
         *     using EnumerableSet for EnumerableSet.AddressSet;
         *
         *     // Declare a set state variable
         *     EnumerableSet.AddressSet private mySet;
         * }
         * ```
         *
         * As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)
         * and `uint256` (`UintSet`) are supported.
         */
        library EnumerableSetUpgradeable {
            // To implement this library for multiple types with as little code
            // repetition as possible, we write it in terms of a generic Set type with
            // bytes32 values.
            // The Set implementation uses private functions, and user-facing
            // implementations (such as AddressSet) are just wrappers around the
            // underlying Set.
            // This means that we can only create new EnumerableSets for types that fit
            // in bytes32.
            struct Set {
                // Storage of set values
                bytes32[] _values;
                // Position of the value in the `values` array, plus 1 because index 0
                // means a value is not in the set.
                mapping (bytes32 => uint256) _indexes;
            }
            /**
             * @dev Add a value to a set. O(1).
             *
             * Returns true if the value was added to the set, that is if it was not
             * already present.
             */
            function _add(Set storage set, bytes32 value) private returns (bool) {
                if (!_contains(set, value)) {
                    set._values.push(value);
                    // The value is stored at length-1, but we add 1 to all indexes
                    // and use 0 as a sentinel value
                    set._indexes[value] = set._values.length;
                    return true;
                } else {
                    return false;
                }
            }
            /**
             * @dev Removes a value from a set. O(1).
             *
             * Returns true if the value was removed from the set, that is if it was
             * present.
             */
            function _remove(Set storage set, bytes32 value) private returns (bool) {
                // We read and store the value's index to prevent multiple reads from the same storage slot
                uint256 valueIndex = set._indexes[value];
                if (valueIndex != 0) { // Equivalent to contains(set, value)
                    // To delete an element from the _values array in O(1), we swap the element to delete with the last one in
                    // the array, and then remove the last element (sometimes called as 'swap and pop').
                    // This modifies the order of the array, as noted in {at}.
                    uint256 toDeleteIndex = valueIndex - 1;
                    uint256 lastIndex = set._values.length - 1;
                    // When the value to delete is the last one, the swap operation is unnecessary. However, since this occurs
                    // so rarely, we still do the swap anyway to avoid the gas cost of adding an 'if' statement.
                    bytes32 lastvalue = set._values[lastIndex];
                    // Move the last value to the index where the value to delete is
                    set._values[toDeleteIndex] = lastvalue;
                    // Update the index for the moved value
                    set._indexes[lastvalue] = toDeleteIndex + 1; // All indexes are 1-based
                    // Delete the slot where the moved value was stored
                    set._values.pop();
                    // Delete the index for the deleted slot
                    delete set._indexes[value];
                    return true;
                } else {
                    return false;
                }
            }
            /**
             * @dev Returns true if the value is in the set. O(1).
             */
            function _contains(Set storage set, bytes32 value) private view returns (bool) {
                return set._indexes[value] != 0;
            }
            /**
             * @dev Returns the number of values on the set. O(1).
             */
            function _length(Set storage set) private view returns (uint256) {
                return set._values.length;
            }
           /**
            * @dev Returns the value stored at position `index` in the set. O(1).
            *
            * Note that there are no guarantees on the ordering of values inside the
            * array, and it may change when more values are added or removed.
            *
            * Requirements:
            *
            * - `index` must be strictly less than {length}.
            */
            function _at(Set storage set, uint256 index) private view returns (bytes32) {
                require(set._values.length > index, "EnumerableSet: index out of bounds");
                return set._values[index];
            }
            // Bytes32Set
            struct Bytes32Set {
                Set _inner;
            }
            /**
             * @dev Add a value to a set. O(1).
             *
             * Returns true if the value was added to the set, that is if it was not
             * already present.
             */
            function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
                return _add(set._inner, value);
            }
            /**
             * @dev Removes a value from a set. O(1).
             *
             * Returns true if the value was removed from the set, that is if it was
             * present.
             */
            function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
                return _remove(set._inner, value);
            }
            /**
             * @dev Returns true if the value is in the set. O(1).
             */
            function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
                return _contains(set._inner, value);
            }
            /**
             * @dev Returns the number of values in the set. O(1).
             */
            function length(Bytes32Set storage set) internal view returns (uint256) {
                return _length(set._inner);
            }
           /**
            * @dev Returns the value stored at position `index` in the set. O(1).
            *
            * Note that there are no guarantees on the ordering of values inside the
            * array, and it may change when more values are added or removed.
            *
            * Requirements:
            *
            * - `index` must be strictly less than {length}.
            */
            function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
                return _at(set._inner, index);
            }
            // AddressSet
            struct AddressSet {
                Set _inner;
            }
            /**
             * @dev Add a value to a set. O(1).
             *
             * Returns true if the value was added to the set, that is if it was not
             * already present.
             */
            function add(AddressSet storage set, address value) internal returns (bool) {
                return _add(set._inner, bytes32(uint256(uint160(value))));
            }
            /**
             * @dev Removes a value from a set. O(1).
             *
             * Returns true if the value was removed from the set, that is if it was
             * present.
             */
            function remove(AddressSet storage set, address value) internal returns (bool) {
                return _remove(set._inner, bytes32(uint256(uint160(value))));
            }
            /**
             * @dev Returns true if the value is in the set. O(1).
             */
            function contains(AddressSet storage set, address value) internal view returns (bool) {
                return _contains(set._inner, bytes32(uint256(uint160(value))));
            }
            /**
             * @dev Returns the number of values in the set. O(1).
             */
            function length(AddressSet storage set) internal view returns (uint256) {
                return _length(set._inner);
            }
           /**
            * @dev Returns the value stored at position `index` in the set. O(1).
            *
            * Note that there are no guarantees on the ordering of values inside the
            * array, and it may change when more values are added or removed.
            *
            * Requirements:
            *
            * - `index` must be strictly less than {length}.
            */
            function at(AddressSet storage set, uint256 index) internal view returns (address) {
                return address(uint160(uint256(_at(set._inner, index))));
            }
            // UintSet
            struct UintSet {
                Set _inner;
            }
            /**
             * @dev Add a value to a set. O(1).
             *
             * Returns true if the value was added to the set, that is if it was not
             * already present.
             */
            function add(UintSet storage set, uint256 value) internal returns (bool) {
                return _add(set._inner, bytes32(value));
            }
            /**
             * @dev Removes a value from a set. O(1).
             *
             * Returns true if the value was removed from the set, that is if it was
             * present.
             */
            function remove(UintSet storage set, uint256 value) internal returns (bool) {
                return _remove(set._inner, bytes32(value));
            }
            /**
             * @dev Returns true if the value is in the set. O(1).
             */
            function contains(UintSet storage set, uint256 value) internal view returns (bool) {
                return _contains(set._inner, bytes32(value));
            }
            /**
             * @dev Returns the number of values on the set. O(1).
             */
            function length(UintSet storage set) internal view returns (uint256) {
                return _length(set._inner);
            }
           /**
            * @dev Returns the value stored at position `index` in the set. O(1).
            *
            * Note that there are no guarantees on the ordering of values inside the
            * array, and it may change when more values are added or removed.
            *
            * Requirements:
            *
            * - `index` must be strictly less than {length}.
            */
            function at(UintSet storage set, uint256 index) internal view returns (uint256) {
                return uint256(_at(set._inner, index));
            }
        }
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.7.0;
        /**
         * @dev Library for managing an enumerable variant of Solidity's
         * https://solidity.readthedocs.io/en/latest/types.html#mapping-types[`mapping`]
         * type.
         *
         * Maps have the following properties:
         *
         * - Entries are added, removed, and checked for existence in constant time
         * (O(1)).
         * - Entries are enumerated in O(n). No guarantees are made on the ordering.
         *
         * ```
         * contract Example {
         *     // Add the library methods
         *     using EnumerableMap for EnumerableMap.UintToAddressMap;
         *
         *     // Declare a set state variable
         *     EnumerableMap.UintToAddressMap private myMap;
         * }
         * ```
         *
         * As of v3.0.0, only maps of type `uint256 -> address` (`UintToAddressMap`) are
         * supported.
         */
        library EnumerableMapUpgradeable {
            // To implement this library for multiple types with as little code
            // repetition as possible, we write it in terms of a generic Map type with
            // bytes32 keys and values.
            // The Map implementation uses private functions, and user-facing
            // implementations (such as Uint256ToAddressMap) are just wrappers around
            // the underlying Map.
            // This means that we can only create new EnumerableMaps for types that fit
            // in bytes32.
            struct MapEntry {
                bytes32 _key;
                bytes32 _value;
            }
            struct Map {
                // Storage of map keys and values
                MapEntry[] _entries;
                // Position of the entry defined by a key in the `entries` array, plus 1
                // because index 0 means a key is not in the map.
                mapping (bytes32 => uint256) _indexes;
            }
            /**
             * @dev Adds a key-value pair to a map, or updates the value for an existing
             * key. O(1).
             *
             * Returns true if the key was added to the map, that is if it was not
             * already present.
             */
            function _set(Map storage map, bytes32 key, bytes32 value) private returns (bool) {
                // We read and store the key's index to prevent multiple reads from the same storage slot
                uint256 keyIndex = map._indexes[key];
                if (keyIndex == 0) { // Equivalent to !contains(map, key)
                    map._entries.push(MapEntry({ _key: key, _value: value }));
                    // The entry is stored at length-1, but we add 1 to all indexes
                    // and use 0 as a sentinel value
                    map._indexes[key] = map._entries.length;
                    return true;
                } else {
                    map._entries[keyIndex - 1]._value = value;
                    return false;
                }
            }
            /**
             * @dev Removes a key-value pair from a map. O(1).
             *
             * Returns true if the key was removed from the map, that is if it was present.
             */
            function _remove(Map storage map, bytes32 key) private returns (bool) {
                // We read and store the key's index to prevent multiple reads from the same storage slot
                uint256 keyIndex = map._indexes[key];
                if (keyIndex != 0) { // Equivalent to contains(map, key)
                    // To delete a key-value pair from the _entries array in O(1), we swap the entry to delete with the last one
                    // in the array, and then remove the last entry (sometimes called as 'swap and pop').
                    // This modifies the order of the array, as noted in {at}.
                    uint256 toDeleteIndex = keyIndex - 1;
                    uint256 lastIndex = map._entries.length - 1;
                    // When the entry to delete is the last one, the swap operation is unnecessary. However, since this occurs
                    // so rarely, we still do the swap anyway to avoid the gas cost of adding an 'if' statement.
                    MapEntry storage lastEntry = map._entries[lastIndex];
                    // Move the last entry to the index where the entry to delete is
                    map._entries[toDeleteIndex] = lastEntry;
                    // Update the index for the moved entry
                    map._indexes[lastEntry._key] = toDeleteIndex + 1; // All indexes are 1-based
                    // Delete the slot where the moved entry was stored
                    map._entries.pop();
                    // Delete the index for the deleted slot
                    delete map._indexes[key];
                    return true;
                } else {
                    return false;
                }
            }
            /**
             * @dev Returns true if the key is in the map. O(1).
             */
            function _contains(Map storage map, bytes32 key) private view returns (bool) {
                return map._indexes[key] != 0;
            }
            /**
             * @dev Returns the number of key-value pairs in the map. O(1).
             */
            function _length(Map storage map) private view returns (uint256) {
                return map._entries.length;
            }
           /**
            * @dev Returns the key-value pair stored at position `index` in the map. O(1).
            *
            * Note that there are no guarantees on the ordering of entries inside the
            * array, and it may change when more entries are added or removed.
            *
            * Requirements:
            *
            * - `index` must be strictly less than {length}.
            */
            function _at(Map storage map, uint256 index) private view returns (bytes32, bytes32) {
                require(map._entries.length > index, "EnumerableMap: index out of bounds");
                MapEntry storage entry = map._entries[index];
                return (entry._key, entry._value);
            }
            /**
             * @dev Tries to returns the value associated with `key`.  O(1).
             * Does not revert if `key` is not in the map.
             */
            function _tryGet(Map storage map, bytes32 key) private view returns (bool, bytes32) {
                uint256 keyIndex = map._indexes[key];
                if (keyIndex == 0) return (false, 0); // Equivalent to contains(map, key)
                return (true, map._entries[keyIndex - 1]._value); // All indexes are 1-based
            }
            /**
             * @dev Returns the value associated with `key`.  O(1).
             *
             * Requirements:
             *
             * - `key` must be in the map.
             */
            function _get(Map storage map, bytes32 key) private view returns (bytes32) {
                uint256 keyIndex = map._indexes[key];
                require(keyIndex != 0, "EnumerableMap: nonexistent key"); // Equivalent to contains(map, key)
                return map._entries[keyIndex - 1]._value; // All indexes are 1-based
            }
            /**
             * @dev Same as {_get}, with a custom error message when `key` is not in the map.
             *
             * CAUTION: This function is deprecated because it requires allocating memory for the error
             * message unnecessarily. For custom revert reasons use {_tryGet}.
             */
            function _get(Map storage map, bytes32 key, string memory errorMessage) private view returns (bytes32) {
                uint256 keyIndex = map._indexes[key];
                require(keyIndex != 0, errorMessage); // Equivalent to contains(map, key)
                return map._entries[keyIndex - 1]._value; // All indexes are 1-based
            }
            // UintToAddressMap
            struct UintToAddressMap {
                Map _inner;
            }
            /**
             * @dev Adds a key-value pair to a map, or updates the value for an existing
             * key. O(1).
             *
             * Returns true if the key was added to the map, that is if it was not
             * already present.
             */
            function set(UintToAddressMap storage map, uint256 key, address value) internal returns (bool) {
                return _set(map._inner, bytes32(key), bytes32(uint256(uint160(value))));
            }
            /**
             * @dev Removes a value from a set. O(1).
             *
             * Returns true if the key was removed from the map, that is if it was present.
             */
            function remove(UintToAddressMap storage map, uint256 key) internal returns (bool) {
                return _remove(map._inner, bytes32(key));
            }
            /**
             * @dev Returns true if the key is in the map. O(1).
             */
            function contains(UintToAddressMap storage map, uint256 key) internal view returns (bool) {
                return _contains(map._inner, bytes32(key));
            }
            /**
             * @dev Returns the number of elements in the map. O(1).
             */
            function length(UintToAddressMap storage map) internal view returns (uint256) {
                return _length(map._inner);
            }
           /**
            * @dev Returns the element stored at position `index` in the set. O(1).
            * Note that there are no guarantees on the ordering of values inside the
            * array, and it may change when more values are added or removed.
            *
            * Requirements:
            *
            * - `index` must be strictly less than {length}.
            */
            function at(UintToAddressMap storage map, uint256 index) internal view returns (uint256, address) {
                (bytes32 key, bytes32 value) = _at(map._inner, index);
                return (uint256(key), address(uint160(uint256(value))));
            }
            /**
             * @dev Tries to returns the value associated with `key`.  O(1).
             * Does not revert if `key` is not in the map.
             *
             * _Available since v3.4._
             */
            function tryGet(UintToAddressMap storage map, uint256 key) internal view returns (bool, address) {
                (bool success, bytes32 value) = _tryGet(map._inner, bytes32(key));
                return (success, address(uint160(uint256(value))));
            }
            /**
             * @dev Returns the value associated with `key`.  O(1).
             *
             * Requirements:
             *
             * - `key` must be in the map.
             */
            function get(UintToAddressMap storage map, uint256 key) internal view returns (address) {
                return address(uint160(uint256(_get(map._inner, bytes32(key)))));
            }
            /**
             * @dev Same as {get}, with a custom error message when `key` is not in the map.
             *
             * CAUTION: This function is deprecated because it requires allocating memory for the error
             * message unnecessarily. For custom revert reasons use {tryGet}.
             */
            function get(UintToAddressMap storage map, uint256 key, string memory errorMessage) internal view returns (address) {
                return address(uint160(uint256(_get(map._inner, bytes32(key), errorMessage))));
            }
        }
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.7.0;
        /**
         * @dev String operations.
         */
        library StringsUpgradeable {
            /**
             * @dev Converts a `uint256` to its ASCII `string` representation.
             */
            function toString(uint256 value) internal pure returns (string memory) {
                // Inspired by OraclizeAPI's implementation - MIT licence
                // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol
                if (value == 0) {
                    return "0";
                }
                uint256 temp = value;
                uint256 digits;
                while (temp != 0) {
                    digits++;
                    temp /= 10;
                }
                bytes memory buffer = new bytes(digits);
                uint256 index = digits - 1;
                temp = value;
                while (temp != 0) {
                    buffer[index--] = bytes1(uint8(48 + temp % 10));
                    temp /= 10;
                }
                return string(buffer);
            }
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        /**
         * @notice Interface for AdminRole which wraps the default admin role from
         * OpenZeppelin's AccessControl for easy integration.
         */
        interface IAdminRole {
          function isAdmin(address account) external view returns (bool);
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        /**
         * @notice Interface for OperatorRole which wraps a role from
         * OpenZeppelin's AccessControl for easy integration.
         */
        interface IOperatorRole {
          function isOperator(address account) external view returns (bool);
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        // solhint-disable
        pragma solidity ^0.7.0;
        interface IFNDNFTMarket {
          function getFeeConfig()
            external
            view
            returns (
              uint256 primaryFoundationFeeBasisPoints,
              uint256 secondaryFoundationFeeBasisPoints,
              uint256 secondaryCreatorFeeBasisPoints
            );
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        library BytesLibrary {
          function replaceAtIf(
            bytes memory data,
            uint256 startLocation,
            address expectedAddress,
            address newAddress
          ) internal pure {
            bytes memory expectedData = abi.encodePacked(expectedAddress);
            bytes memory newData = abi.encodePacked(newAddress);
            // An address is 20 bytes long
            for (uint256 i = 0; i < 20; i++) {
              uint256 dataLocation = startLocation + i;
              require(data[dataLocation] == expectedData[i], "Bytes: Data provided does not include the expectedAddress");
              data[dataLocation] = newData[i];
            }
          }
        }
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.7.0;
        /**
         * @dev Elliptic Curve Digital Signature Algorithm (ECDSA) operations.
         *
         * These functions can be used to verify that a message was signed by the holder
         * of the private keys of a given address.
         */
        library ECDSA {
            /**
             * @dev Returns the address that signed a hashed message (`hash`) with
             * `signature`. This address can then be used for verification purposes.
             *
             * The `ecrecover` EVM opcode allows for malleable (non-unique) signatures:
             * this function rejects them by requiring the `s` value to be in the lower
             * half order, and the `v` value to be either 27 or 28.
             *
             * IMPORTANT: `hash` _must_ be the result of a hash operation for the
             * verification to be secure: it is possible to craft signatures that
             * recover to arbitrary addresses for non-hashed data. A safe way to ensure
             * this is by receiving a hash of the original message (which may otherwise
             * be too long), and then calling {toEthSignedMessageHash} on it.
             */
            function recover(bytes32 hash, bytes memory signature) internal pure returns (address) {
                // Check the signature length
                if (signature.length != 65) {
                    revert("ECDSA: invalid signature length");
                }
                // Divide the signature in r, s and v variables
                bytes32 r;
                bytes32 s;
                uint8 v;
                // ecrecover takes the signature parameters, and the only way to get them
                // currently is to use assembly.
                // solhint-disable-next-line no-inline-assembly
                assembly {
                    r := mload(add(signature, 0x20))
                    s := mload(add(signature, 0x40))
                    v := byte(0, mload(add(signature, 0x60)))
                }
                return recover(hash, v, r, s);
            }
            /**
             * @dev Overload of {ECDSA-recover-bytes32-bytes-} that receives the `v`,
             * `r` and `s` signature fields separately.
             */
            function recover(bytes32 hash, uint8 v, bytes32 r, bytes32 s) internal pure returns (address) {
                // EIP-2 still allows signature malleability for ecrecover(). Remove this possibility and make the signature
                // unique. Appendix F in the Ethereum Yellow paper (https://ethereum.github.io/yellowpaper/paper.pdf), defines
                // the valid range for s in (281): 0 < s < secp256k1n ÷ 2 + 1, and for v in (282): v ∈ {27, 28}. Most
                // signatures from current libraries generate a unique signature with an s-value in the lower half order.
                //
                // If your library generates malleable signatures, such as s-values in the upper range, calculate a new s-value
                // with 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 - s1 and flip v from 27 to 28 or
                // vice versa. If your library also generates signatures with 0/1 for v instead 27/28, add 27 to v to accept
                // these malleable signatures as well.
                require(uint256(s) <= 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0, "ECDSA: invalid signature 's' value");
                require(v == 27 || v == 28, "ECDSA: invalid signature 'v' value");
                // If the signature is valid (and not malleable), return the signer address
                address signer = ecrecover(hash, v, r, s);
                require(signer != address(0), "ECDSA: invalid signature");
                return signer;
            }
            /**
             * @dev Returns an Ethereum Signed Message, created from a `hash`. This
             * replicates the behavior of the
             * https://github.com/ethereum/wiki/wiki/JSON-RPC#eth_sign[`eth_sign`]
             * JSON-RPC method.
             *
             * See {recover}.
             */
            function toEthSignedMessageHash(bytes32 hash) internal pure returns (bytes32) {
                // 32 is the length in bytes of hash,
                // enforced by the type signature above
                return keccak256(abi.encodePacked("\\x19Ethereum Signed Message:\
        32", hash));
            }
        }
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.7.0;
        /**
         * @dev Collection of functions related to the address type
         */
        library Address {
            /**
             * @dev Returns true if `account` is a contract.
             *
             * [IMPORTANT]
             * ====
             * It is unsafe to assume that an address for which this function returns
             * false is an externally-owned account (EOA) and not a contract.
             *
             * Among others, `isContract` will return false for the following
             * types of addresses:
             *
             *  - an externally-owned account
             *  - a contract in construction
             *  - an address where a contract will be created
             *  - an address where a contract lived, but was destroyed
             * ====
             */
            function isContract(address account) internal view returns (bool) {
                // This method relies on extcodesize, which returns 0 for contracts in
                // construction, since the code is only stored at the end of the
                // constructor execution.
                uint256 size;
                // solhint-disable-next-line no-inline-assembly
                assembly { size := extcodesize(account) }
                return size > 0;
            }
            /**
             * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
             * `recipient`, forwarding all available gas and reverting on errors.
             *
             * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
             * of certain opcodes, possibly making contracts go over the 2300 gas limit
             * imposed by `transfer`, making them unable to receive funds via
             * `transfer`. {sendValue} removes this limitation.
             *
             * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
             *
             * IMPORTANT: because control is transferred to `recipient`, care must be
             * taken to not create reentrancy vulnerabilities. Consider using
             * {ReentrancyGuard} or the
             * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
             */
            function sendValue(address payable recipient, uint256 amount) internal {
                require(address(this).balance >= amount, "Address: insufficient balance");
                // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
                (bool success, ) = recipient.call{ value: amount }("");
                require(success, "Address: unable to send value, recipient may have reverted");
            }
            /**
             * @dev Performs a Solidity function call using a low level `call`. A
             * plain`call` is an unsafe replacement for a function call: use this
             * function instead.
             *
             * If `target` reverts with a revert reason, it is bubbled up by this
             * function (like regular Solidity function calls).
             *
             * Returns the raw returned data. To convert to the expected return value,
             * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
             *
             * Requirements:
             *
             * - `target` must be a contract.
             * - calling `target` with `data` must not revert.
             *
             * _Available since v3.1._
             */
            function functionCall(address target, bytes memory data) internal returns (bytes memory) {
              return functionCall(target, data, "Address: low-level call failed");
            }
            /**
             * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
             * `errorMessage` as a fallback revert reason when `target` reverts.
             *
             * _Available since v3.1._
             */
            function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
                return functionCallWithValue(target, data, 0, errorMessage);
            }
            /**
             * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
             * but also transferring `value` wei to `target`.
             *
             * Requirements:
             *
             * - the calling contract must have an ETH balance of at least `value`.
             * - the called Solidity function must be `payable`.
             *
             * _Available since v3.1._
             */
            function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
                return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
            }
            /**
             * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
             * with `errorMessage` as a fallback revert reason when `target` reverts.
             *
             * _Available since v3.1._
             */
            function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
                require(address(this).balance >= value, "Address: insufficient balance for call");
                require(isContract(target), "Address: call to non-contract");
                // solhint-disable-next-line avoid-low-level-calls
                (bool success, bytes memory returndata) = target.call{ value: value }(data);
                return _verifyCallResult(success, returndata, errorMessage);
            }
            /**
             * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
             * but performing a static call.
             *
             * _Available since v3.3._
             */
            function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                return functionStaticCall(target, data, "Address: low-level static call failed");
            }
            /**
             * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
             * but performing a static call.
             *
             * _Available since v3.3._
             */
            function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
                require(isContract(target), "Address: static call to non-contract");
                // solhint-disable-next-line avoid-low-level-calls
                (bool success, bytes memory returndata) = target.staticcall(data);
                return _verifyCallResult(success, returndata, errorMessage);
            }
            /**
             * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
             * but performing a delegate call.
             *
             * _Available since v3.4._
             */
            function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
                return functionDelegateCall(target, data, "Address: low-level delegate call failed");
            }
            /**
             * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
             * but performing a delegate call.
             *
             * _Available since v3.4._
             */
            function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
                require(isContract(target), "Address: delegate call to non-contract");
                // solhint-disable-next-line avoid-low-level-calls
                (bool success, bytes memory returndata) = target.delegatecall(data);
                return _verifyCallResult(success, returndata, errorMessage);
            }
            function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
                if (success) {
                    return returndata;
                } else {
                    // Look for revert reason and bubble it up if present
                    if (returndata.length > 0) {
                        // The easiest way to bubble the revert reason is using memory via assembly
                        // solhint-disable-next-line no-inline-assembly
                        assembly {
                            let returndata_size := mload(returndata)
                            revert(add(32, returndata), returndata_size)
                        }
                    } else {
                        revert(errorMessage);
                    }
                }
            }
        }
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.7.0;
        /**
         * @dev String operations.
         */
        library Strings {
            /**
             * @dev Converts a `uint256` to its ASCII `string` representation.
             */
            function toString(uint256 value) internal pure returns (string memory) {
                // Inspired by OraclizeAPI's implementation - MIT licence
                // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol
                if (value == 0) {
                    return "0";
                }
                uint256 temp = value;
                uint256 digits;
                while (temp != 0) {
                    digits++;
                    temp /= 10;
                }
                bytes memory buffer = new bytes(digits);
                uint256 index = digits - 1;
                temp = value;
                while (temp != 0) {
                    buffer[index--] = bytes1(uint8(48 + temp % 10));
                    temp /= 10;
                }
                return string(buffer);
            }
        }
        // SPDX-License-Identifier: MIT
        pragma solidity ^0.7.0;
        /**
         * @dev Interface of the ERC1271 standard signature validation method for
         * contracts as defined in https://eips.ethereum.org/EIPS/eip-1271[ERC-1271].
         *
         * from https://github.com/OpenZeppelin/openzeppelin-contracts/blob/v4.1.0/contracts/interfaces/IERC1271.sol
         */
        interface IERC1271 {
          /**
           * @dev Should return whether the signature provided is valid for the provided data
           * @param hash      Hash of the data to be signed
           * @param signature Signature byte array associated with _data
           */
          function isValidSignature(bytes32 hash, bytes memory signature) external view returns (bytes4 magicValue);
        }
        // SPDX-License-Identifier: MIT OR Apache-2.0
        pragma solidity ^0.7.0;
        interface IProxyCall {
          function proxyCallAndReturnAddress(address externalContract, bytes calldata callData)
            external
            returns (address payable result);
        }