ETH Price: $1,948.08 (+1.41%)
Gas: 0.12 Gwei

Transaction Decoder

Block:
16170824 at Dec-12-2022 07:51:23 PM +UTC
Transaction Fee:
0.001060802656510104 ETH $2.07
Gas Used:
53,562 Gas / 19.805135292 Gwei

Emitted Events:

273 TransparentUpgradeableProxy.0x17307eab39ab6107e8899845ad3d59bd9653f200f220920489ca2b5937696c31( 0x17307eab39ab6107e8899845ad3d59bd9653f200f220920489ca2b5937696c31, 0x00000000000000000000000017ab241effbf26e55169a3ea20a8a8214ea9eb84, 0x0000000000000000000000001e0049783f008a0085193e00003d00cd54003c71, 0000000000000000000000000000000000000000000000000000000000000001 )

Account State Difference:

  Address   Before After State Difference Code
0x17ab241e...14EA9eB84
0.096332408501674708 Eth
Nonce: 311
0.095271605845164604 Eth
Nonce: 312
0.001060802656510104
(beaverbuild)
201.945617366714028093 Eth201.945697709714028093 Eth0.000080343
0xA37c76Dc...2340af430

Execution Trace

TransparentUpgradeableProxy.a22cb465( )
  • Scientist.setApprovalForAll( operator=0x1E0049783F008A0085193E00003D00cd54003c71, approved=True )
    File 1 of 2: TransparentUpgradeableProxy
    // File: @openzeppelin\contracts\proxy\Proxy.sol
    
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.6.0) (proxy/Proxy.sol)
    
    pragma solidity ^0.8.0;
    
    /**
     * @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
     * instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to
     * be specified by overriding the virtual {_implementation} function.
     *
     * Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
     * different contract through the {_delegate} function.
     *
     * The success and return data of the delegated call will be returned back to the caller of the proxy.
     */
    abstract contract Proxy {
        /**
         * @dev Delegates the current call to `implementation`.
         *
         * This function does not return to its internal call site, it will return directly to the external caller.
         */
        function _delegate(address implementation) internal virtual {
            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 This is a virtual function that should be overridden so it returns the address to which the fallback function
         * and {_fallback} should delegate.
         */
        function _implementation() internal view virtual returns (address);
    
        /**
         * @dev Delegates the current call to the address returned by `_implementation()`.
         *
         * This function does not return to its internal call site, it will return directly to the external caller.
         */
        function _fallback() internal virtual {
            _beforeFallback();
            _delegate(_implementation());
        }
    
        /**
         * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other
         * function in the contract matches the call data.
         */
        fallback() external payable virtual {
            _fallback();
        }
    
        /**
         * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
         * is empty.
         */
        receive() external payable virtual {
            _fallback();
        }
    
        /**
         * @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback`
         * call, or as part of the Solidity `fallback` or `receive` functions.
         *
         * If overridden should call `super._beforeFallback()`.
         */
        function _beforeFallback() internal virtual {}
    }
    
    // File: @openzeppelin\contracts\proxy\beacon\IBeacon.sol
    
    // OpenZeppelin Contracts v4.4.1 (proxy/beacon/IBeacon.sol)
    
    pragma solidity ^0.8.0;
    
    /**
     * @dev This is the interface that {BeaconProxy} expects of its beacon.
     */
    interface IBeacon {
        /**
         * @dev Must return an address that can be used as a delegate call target.
         *
         * {BeaconProxy} will check that this address is a contract.
         */
        function implementation() external view returns (address);
    }
    
    // File: @openzeppelin\contracts\interfaces\draft-IERC1822.sol
    
    // OpenZeppelin Contracts (last updated v4.5.0) (interfaces/draft-IERC1822.sol)
    
    pragma solidity ^0.8.0;
    
    /**
     * @dev ERC1822: Universal Upgradeable Proxy Standard (UUPS) documents a method for upgradeability through a simplified
     * proxy whose upgrades are fully controlled by the current implementation.
     */
    interface IERC1822Proxiable {
        /**
         * @dev Returns the storage slot that the proxiable contract assumes is being used to store the implementation
         * address.
         *
         * IMPORTANT: A proxy pointing at a proxiable contract should not be considered proxiable itself, because this risks
         * bricking a proxy that upgrades to it, by delegating to itself until out of gas. Thus it is critical that this
         * function revert if invoked through a proxy.
         */
        function proxiableUUID() external view returns (bytes32);
    }
    
    // File: @openzeppelin\contracts\utils\Address.sol
    
    // OpenZeppelin Contracts (last updated v4.7.0) (utils/Address.sol)
    
    pragma solidity ^0.8.1;
    
    /**
     * @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
         * ====
         *
         * [IMPORTANT]
         * ====
         * You shouldn't rely on `isContract` to protect against flash loan attacks!
         *
         * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
         * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
         * constructor.
         * ====
         */
        function isContract(address account) internal view returns (bool) {
            // This method relies on extcodesize/address.code.length, which returns 0
            // for contracts in construction, since the code is only stored at the end
            // of the constructor execution.
    
            return account.code.length > 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");
    
            (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");
    
            (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");
    
            (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");
    
            (bool success, bytes memory returndata) = target.delegatecall(data);
            return verifyCallResult(success, returndata, errorMessage);
        }
    
        /**
         * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
         * revert reason using the provided one.
         *
         * _Available since v4.3._
         */
        function verifyCallResult(
            bool success,
            bytes memory returndata,
            string memory errorMessage
        ) internal 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
                    /// @solidity memory-safe-assembly
                    assembly {
                        let returndata_size := mload(returndata)
                        revert(add(32, returndata), returndata_size)
                    }
                } else {
                    revert(errorMessage);
                }
            }
        }
    }
    
    // File: @openzeppelin\contracts\utils\StorageSlot.sol
    
    // OpenZeppelin Contracts (last updated v4.7.0) (utils/StorageSlot.sol)
    
    pragma solidity ^0.8.0;
    
    /**
     * @dev Library for reading and writing primitive types to specific storage slots.
     *
     * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
     * This library helps with reading and writing to such slots without the need for inline assembly.
     *
     * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
     *
     * Example usage to set ERC1967 implementation slot:
     * ```
     * contract ERC1967 {
     *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
     *
     *     function _getImplementation() internal view returns (address) {
     *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
     *     }
     *
     *     function _setImplementation(address newImplementation) internal {
     *         require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
     *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
     *     }
     * }
     * ```
     *
     * _Available since v4.1 for `address`, `bool`, `bytes32`, and `uint256`._
     */
    library StorageSlot {
        struct AddressSlot {
            address value;
        }
    
        struct BooleanSlot {
            bool value;
        }
    
        struct Bytes32Slot {
            bytes32 value;
        }
    
        struct Uint256Slot {
            uint256 value;
        }
    
        /**
         * @dev Returns an `AddressSlot` with member `value` located at `slot`.
         */
        function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
            /// @solidity memory-safe-assembly
            assembly {
                r.slot := slot
            }
        }
    
        /**
         * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
         */
        function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
            /// @solidity memory-safe-assembly
            assembly {
                r.slot := slot
            }
        }
    
        /**
         * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
         */
        function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
            /// @solidity memory-safe-assembly
            assembly {
                r.slot := slot
            }
        }
    
        /**
         * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
         */
        function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
            /// @solidity memory-safe-assembly
            assembly {
                r.slot := slot
            }
        }
    }
    
    // File: @openzeppelin\contracts\proxy\ERC1967\ERC1967Upgrade.sol
    
    // OpenZeppelin Contracts (last updated v4.5.0) (proxy/ERC1967/ERC1967Upgrade.sol)
    
    pragma solidity ^0.8.2;
    
    
    
    
    /**
     * @dev This abstract contract provides getters and event emitting update functions for
     * https://eips.ethereum.org/EIPS/eip-1967[EIP1967] slots.
     *
     * _Available since v4.1._
     *
     * @custom:oz-upgrades-unsafe-allow delegatecall
     */
    abstract contract ERC1967Upgrade {
        // This is the keccak-256 hash of "eip1967.proxy.rollback" subtracted by 1
        bytes32 private constant _ROLLBACK_SLOT = 0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;
    
        /**
         * @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 Emitted when the implementation is upgraded.
         */
        event Upgraded(address indexed implementation);
    
        /**
         * @dev Returns the current implementation address.
         */
        function _getImplementation() internal view returns (address) {
            return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
        }
    
        /**
         * @dev Stores a new address in the EIP1967 implementation slot.
         */
        function _setImplementation(address newImplementation) private {
            require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
            StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
        }
    
        /**
         * @dev Perform implementation upgrade
         *
         * Emits an {Upgraded} event.
         */
        function _upgradeTo(address newImplementation) internal {
            _setImplementation(newImplementation);
            emit Upgraded(newImplementation);
        }
    
        /**
         * @dev Perform implementation upgrade with additional setup call.
         *
         * Emits an {Upgraded} event.
         */
        function _upgradeToAndCall(
            address newImplementation,
            bytes memory data,
            bool forceCall
        ) internal {
            _upgradeTo(newImplementation);
            if (data.length > 0 || forceCall) {
                Address.functionDelegateCall(newImplementation, data);
            }
        }
    
        /**
         * @dev Perform implementation upgrade with security checks for UUPS proxies, and additional setup call.
         *
         * Emits an {Upgraded} event.
         */
        function _upgradeToAndCallUUPS(
            address newImplementation,
            bytes memory data,
            bool forceCall
        ) internal {
            // Upgrades from old implementations will perform a rollback test. This test requires the new
            // implementation to upgrade back to the old, non-ERC1822 compliant, implementation. Removing
            // this special case will break upgrade paths from old UUPS implementation to new ones.
            if (StorageSlot.getBooleanSlot(_ROLLBACK_SLOT).value) {
                _setImplementation(newImplementation);
            } else {
                try IERC1822Proxiable(newImplementation).proxiableUUID() returns (bytes32 slot) {
                    require(slot == _IMPLEMENTATION_SLOT, "ERC1967Upgrade: unsupported proxiableUUID");
                } catch {
                    revert("ERC1967Upgrade: new implementation is not UUPS");
                }
                _upgradeToAndCall(newImplementation, data, forceCall);
            }
        }
    
        /**
         * @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 Emitted when the admin account has changed.
         */
        event AdminChanged(address previousAdmin, address newAdmin);
    
        /**
         * @dev Returns the current admin.
         */
        function _getAdmin() internal view returns (address) {
            return StorageSlot.getAddressSlot(_ADMIN_SLOT).value;
        }
    
        /**
         * @dev Stores a new address in the EIP1967 admin slot.
         */
        function _setAdmin(address newAdmin) private {
            require(newAdmin != address(0), "ERC1967: new admin is the zero address");
            StorageSlot.getAddressSlot(_ADMIN_SLOT).value = newAdmin;
        }
    
        /**
         * @dev Changes the admin of the proxy.
         *
         * Emits an {AdminChanged} event.
         */
        function _changeAdmin(address newAdmin) internal {
            emit AdminChanged(_getAdmin(), newAdmin);
            _setAdmin(newAdmin);
        }
    
        /**
         * @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
         * This is bytes32(uint256(keccak256('eip1967.proxy.beacon')) - 1)) and is validated in the constructor.
         */
        bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;
    
        /**
         * @dev Emitted when the beacon is upgraded.
         */
        event BeaconUpgraded(address indexed beacon);
    
        /**
         * @dev Returns the current beacon.
         */
        function _getBeacon() internal view returns (address) {
            return StorageSlot.getAddressSlot(_BEACON_SLOT).value;
        }
    
        /**
         * @dev Stores a new beacon in the EIP1967 beacon slot.
         */
        function _setBeacon(address newBeacon) private {
            require(Address.isContract(newBeacon), "ERC1967: new beacon is not a contract");
            require(
                Address.isContract(IBeacon(newBeacon).implementation()),
                "ERC1967: beacon implementation is not a contract"
            );
            StorageSlot.getAddressSlot(_BEACON_SLOT).value = newBeacon;
        }
    
        /**
         * @dev Perform beacon upgrade with additional setup call. Note: This upgrades the address of the beacon, it does
         * not upgrade the implementation contained in the beacon (see {UpgradeableBeacon-_setImplementation} for that).
         *
         * Emits a {BeaconUpgraded} event.
         */
        function _upgradeBeaconToAndCall(
            address newBeacon,
            bytes memory data,
            bool forceCall
        ) internal {
            _setBeacon(newBeacon);
            emit BeaconUpgraded(newBeacon);
            if (data.length > 0 || forceCall) {
                Address.functionDelegateCall(IBeacon(newBeacon).implementation(), data);
            }
        }
    }
    
    // File: @openzeppelin\contracts\proxy\ERC1967\ERC1967Proxy.sol
    
    // OpenZeppelin Contracts (last updated v4.7.0) (proxy/ERC1967/ERC1967Proxy.sol)
    
    pragma solidity ^0.8.0;
    
    
    /**
     * @dev This contract implements an upgradeable proxy. It is upgradeable because calls are delegated to an
     * implementation address that can be changed. This address is stored in storage in the location specified by
     * https://eips.ethereum.org/EIPS/eip-1967[EIP1967], so that it doesn't conflict with the storage layout of the
     * implementation behind the proxy.
     */
    contract ERC1967Proxy is Proxy, ERC1967Upgrade {
        /**
         * @dev Initializes the upgradeable proxy with an initial implementation specified by `_logic`.
         *
         * If `_data` is nonempty, it's used as data in a delegate call to `_logic`. This will typically be an encoded
         * function call, and allows initializing the storage of the proxy like a Solidity constructor.
         */
        constructor(address _logic, bytes memory _data) payable {
            _upgradeToAndCall(_logic, _data, false);
        }
    
        /**
         * @dev Returns the current implementation address.
         */
        function _implementation() internal view virtual override returns (address impl) {
            return ERC1967Upgrade._getImplementation();
        }
    }
    
    // File: contracts\proxy\TransparentUpgradeableProxy.sol
    
    // OpenZeppelin Contracts v4.4.1 (proxy/transparent/TransparentUpgradeableProxy.sol)
    
    pragma solidity ^0.8.2;
    /**
     * @dev This contract implements a proxy that is upgradeable by an admin.
     *
     * To avoid https://medium.com/nomic-labs-blog/malicious-backdoors-in-ethereum-proxies-62629adf3357[proxy selector
     * clashing], which can potentially be used in an attack, this contract uses the
     * https://blog.openzeppelin.com/the-transparent-proxy-pattern/[transparent proxy pattern]. This pattern implies two
     * things that go hand in hand:
     *
     * 1. If any account other than the admin calls the proxy, the call will be forwarded to the implementation, even if
     * that call matches one of the admin functions exposed by the proxy itself.
     * 2. If the admin calls the proxy, it can access the admin functions, but its calls will never be forwarded to the
     * implementation. If the admin tries to call a function on the implementation it will fail with an error that says
     * "admin cannot fallback to proxy target".
     *
     * These properties mean that the admin account can only be used for admin actions like upgrading the proxy or changing
     * the admin, so it's best if it's a dedicated account that is not used for anything else. This will avoid headaches due
     * to sudden errors when trying to call a function from the proxy implementation.
     *
     * Our recommendation is for the dedicated account to be an instance of the {ProxyAdmin} contract. If set up this way,
     * you should think of the `ProxyAdmin` instance as the real administrative interface of your proxy.
     */
    contract TransparentUpgradeableProxy is ERC1967Proxy {
        /**
         * @dev Initializes an upgradeable proxy managed by `_admin`, backed by the implementation at `_logic`, and
         * optionally initialized with `_data` as explained in {ERC1967Proxy-constructor}.
         */
        constructor(
            address _logic,
            address admin_,
            bytes memory _data
        ) payable ERC1967Proxy(_logic, _data) {
            assert(_ADMIN_SLOT == bytes32(uint256(keccak256("eip1967.proxy.admin")) - 1));
            _changeAdmin(admin_);
        }
    
        /**
         * @dev Modifier used internally that will delegate the call to the implementation unless the sender is the admin.
         */
        modifier ifAdmin() {
            if (msg.sender == _getAdmin()) {
                _;
            } else {
                _fallback();
            }
        }
    
        /**
         * @dev Returns the current admin.
         *
         * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyAdmin}.
         *
         * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
         * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
         * `0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103`
         */
        function admin() external ifAdmin returns (address admin_) {
            admin_ = _getAdmin();
        }
    
        /**
         * @dev Returns the current implementation.
         *
         * NOTE: Only the admin can call this function. See {ProxyAdmin-getProxyImplementation}.
         *
         * TIP: To get this value clients can read directly from the storage slot shown below (specified by EIP1967) using the
         * https://eth.wiki/json-rpc/API#eth_getstorageat[`eth_getStorageAt`] RPC call.
         * `0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc`
         */
        function implementation() external ifAdmin returns (address implementation_) {
            implementation_ = _implementation();
        }
    
        /**
         * @dev Changes the admin of the proxy.
         *
         * Emits an {AdminChanged} event.
         *
         * NOTE: Only the admin can call this function. See {ProxyAdmin-changeProxyAdmin}.
         */
        function changeAdmin(address newAdmin) external virtual ifAdmin {
            emit AdminChanged(_getAdmin(), newAdmin);
            StorageSlot.getAddressSlot(_ADMIN_SLOT).value = newAdmin;
        }
    
        /**
         * @dev Upgrade the implementation of the proxy.
         *
         * NOTE: Only the admin can call this function. See {ProxyAdmin-upgrade}.
         */
        function upgradeTo(address newImplementation) external ifAdmin {
            _upgradeToAndCall(newImplementation, bytes(""), false);
        }
    
        /**
         * @dev Upgrade the implementation of the proxy, and then call a function from the new implementation as specified
         * by `data`, which should be an encoded function call. This is useful to initialize new storage variables in the
         * proxied contract.
         *
         * NOTE: Only the admin can call this function. See {ProxyAdmin-upgradeAndCall}.
         */
        function upgradeToAndCall(address newImplementation, bytes calldata data) external payable ifAdmin {
            _upgradeToAndCall(newImplementation, data, true);
        }
    
        /**
         * @dev Returns the current admin.
         */
        function _admin() internal view virtual returns (address) {
            return _getAdmin();
        }
    
        /**
         * @dev Makes sure the admin cannot access the fallback function. See {Proxy-_beforeFallback}.
         */
        function _beforeFallback() internal virtual override {
            require(msg.sender != _getAdmin(), "TransparentUpgradeableProxy: admin cannot fallback to proxy target");
            super._beforeFallback();
        }
    
        function getAdmin() external view returns(address) {
            return _getAdmin();
        }
    
        function getImplementation() external view returns (address) {
            return _implementation();
        }
    }

    File 2 of 2: Scientist
    // SPDX-License-Identifier: GPL-3.0
    pragma solidity ^0.8.3;
    import "@openzeppelin/contracts/utils/cryptography/ECDSA.sol";
    import "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
    import "@openzeppelin/contracts-upgradeable/security/ReentrancyGuardUpgradeable.sol";
    import "@openzeppelin/contracts-upgradeable/security/PausableUpgradeable.sol";
    import "@openzeppelin/contracts-upgradeable/token/common/ERC2981Upgradeable.sol";
    import "../erc721-tradable-upgradeable/ERC721TradableUpgradeable.sol";
    import "./abstracts/AScientistRepository.sol";
    import "./interfaces/IScientistCharacteristic.sol";
    contract Scientist is
        IScientistCharacteristic,
        ERC721TradableUpgradeable,
        ERC2981Upgradeable,
        PausableUpgradeable,
        AScientistRepository,
        ReentrancyGuardUpgradeable,
        OwnableUpgradeable
    {
        using Counters for Counters.Counter;
        using ECDSA for bytes32;
        // Constants
        uint8 public constant LENGTH_OF_SCIENTIFIC_FIELDS = 6;
        uint8 public constant LENGTH_OF_PERSONALITY_DISORDERS = 5;
        uint8 public constant LENGTH_OF_AUTHORITY = 5;
        uint8 public constant LENGTH_OF_CONVENTIONS = 3;
        uint8 public constant LENGTH_OF_VIOLENCE = 6;
        uint8 public constant LENGTH_OF_VICES = 7;
        uint8 public constant LENGTH_OF_MAGNITUDE_OF_STRESS = 7;
        uint256 public constant MAX_MINTABLE = 10500;
        // Variables
        Counters.Counter private tokenIdCount;
        string public baseTokenURI;
        string public contractURI;
        bytes32 public stagesID;
        uint256 public price;
        uint256 public maxClaimed;
        uint256 public mintableAmount;
        uint256 public remainingAmount;
        uint96 public feeNumerator;
        address private proxyRegistryAddress;
        mapping(uint256 => ScientistTraits) public scientistTraits;
        bool public isCanTransfer;
        address public signer;
        mapping(bytes => uint256) public claimedTime;
        // Events
        event SetNewTranche(
            address signer,
            bytes32 stagesID,
            uint256 newPrice,
            uint256 newAmount,
            uint256 newMaxClaimed,
            uint256 timestamp
        );
        event MintForGift(
            address caller,
            address to,
            uint256 tokenId,
            uint256 timestamp
        );
        event SetBaseTokenURI(string uri, uint256 timestamp);
        event SetContractURI(string uri, uint256 timestamp);
        event SetProxyRegistry(address proxy, uint256 timestamp);
        /**
         * @dev validates signature
         */
        modifier isValidSign(
            address to,
            bytes calldata sig,
            uint256 index
        ) {
            bytes32 dataHash = keccak256(abi.encodePacked(to, stagesID, index));
            bytes32 ethSigHash = dataHash.toEthSignedMessageHash();
            require(_verifySig(ethSigHash, sig), "This wallet is not in whitelist");
            require(
                claimedTime[sig] < maxClaimed,
                "This wallet reached claimed times to mint Scientist"
            );
            claimedTime[sig]++;
            _;
        }
        function _verifySig(bytes32 ethSigHash, bytes calldata sig)
            internal
            view
            returns (bool)
        {
            address _signer = ethSigHash.recover(sig);
            require(_signer != address(0), "ECDSA: invalid signature");
            return _signer == signer;
        }
        function claimable(
            address account,
            bytes calldata sig,
            uint256 index
        ) external view returns (bool) {
            bytes32 dataHash = keccak256(
                abi.encodePacked(account, stagesID, index)
            );
            bytes32 ethSigHash = dataHash.toEthSignedMessageHash();
            return _verifySig(ethSigHash, sig) && claimedTime[sig] < maxClaimed;
        }
        function initialize(
            string memory _name,
            string memory _symbol,
            address _proxyRegistryAddress,
            address _timelock
        ) external initializer {
            require(_proxyRegistryAddress != address(0), "Empty address");
            proxyRegistryAddress = _proxyRegistryAddress;
            timelock = _timelock;
            __ERC721_init(_name, _symbol);
            _initializeEIP712(_name);
            __ReentrancyGuard_init();
            __Ownable_init();
            __Pausable_init();
            baseTokenURI = "";
            contractURI = "";
            maxClaimed = 5;
        }
        function getProxyRegistryAddress()
            public
            view
            virtual
            override
            returns (address)
        {
            return proxyRegistryAddress;
        }
        function setProxyRegistryAddress(address newProxyRegistryAddress)
            external
            onlyTimelock
        {
            require(newProxyRegistryAddress != address(0), "Empty address");
            proxyRegistryAddress = newProxyRegistryAddress;
            emit SetProxyRegistry(newProxyRegistryAddress, block.timestamp);
        }
        function setBaseTokenURI(string memory uri) external onlyTimelock {
            baseTokenURI = uri;
            emit SetBaseTokenURI(uri, block.timestamp);
        }
        function setContractURI(string memory uri) external onlyTimelock {
            contractURI = uri;
            emit SetContractURI(uri, block.timestamp);
        }
        function tokenURI(uint256 _tokenId)
            public
            view
            override
            returns (string memory)
        {
            return
                string(
                    abi.encodePacked(
                        baseTokenURI,
                        Strings.toString(_tokenId),
                        ".json"
                    )
                );
        }
        function pause() external onlyTimelock {
            _pause();
        }
        function unpause() external onlyTimelock {
            _unpause();
        }
        function setNewTranche(
            address newSigner,
            bytes32 newStagesID,
            uint256 newPrice,
            uint256 newAmount,
            uint256 newMaxClaimed
        ) external onlyTimelock {
            require(newMaxClaimed > 0, "Invalid value");
            require(newSigner != address(0), "Empty address");
            signer = newSigner;
            maxClaimed = newMaxClaimed;
            stagesID = newStagesID;
            price = newPrice;
            remainingAmount = mintableAmount = newAmount;
            emit SetNewTranche(
                newSigner,
                newStagesID,
                newPrice,
                newAmount,
                newMaxClaimed,
                block.timestamp
            );
        }
        function _customBurn(uint256 tokenId) internal {
            require(scientists[tokenId].onSale == false, "Scientist is on sale");
            _removeScientist(msg.sender, tokenId);
            super._burn(tokenId);
            delete scientists[tokenId];
        }
        function burn(uint256 tokenId) external override {
            require(
                msg.sender == ownerOf(tokenId),
                "Caller is not owner of token id"
            );
            _customBurn(tokenId);
        }
        function _transfer(
            address from,
            address to,
            uint256 tokenId
        ) internal override {
            require(isCanTransfer == true, "Can not transfer at this time");
            _removeScientist(from, tokenId);
            super._transfer(from, to, tokenId);
            _addScientist(to, tokenId);
        }
        function mintFor(
            address to,
            bytes calldata sign,
            uint256 index,
            ScientistTraits memory traits
        )
            external
            payable
            isValidSign(to, sign, index)
            nonReentrant
            isOperator
            whenNotPaused
        {
            _mintForGift(to, traits);
        }
        function mint(address to) external isOperator {
            _create(to);
        }
        function createMultiple(address to, uint256 amount) external isOperator {
            for (uint256 i = 0; i < amount; i++) {
                _create(to);
            }
        }
        function mintForGift(
            address to,
            bytes calldata sign,
            uint256 index,
            ScientistTraits memory traits
        )
            external
            payable
            isValidSign(msg.sender, sign, index)
            nonReentrant
            whenNotPaused
        {
            _mintForGift(to, traits);
        }
        function _mintForGift(address to, ScientistTraits memory traits) internal {
            require(
                traits.scientificField < LENGTH_OF_SCIENTIFIC_FIELDS &&
                    traits.personalityDisorders < LENGTH_OF_PERSONALITY_DISORDERS &&
                    traits.psychologicalForce.obedienceToAuthority <
                    LENGTH_OF_AUTHORITY &&
                    traits.psychologicalForce.obedienceToConventions <
                    LENGTH_OF_CONVENTIONS &&
                    traits.psychologicalForce.tendencyTowardViolence <
                    LENGTH_OF_VIOLENCE &&
                    traits.vice < LENGTH_OF_VICES &&
                    traits.magnitudeOfStress < LENGTH_OF_MAGNITUDE_OF_STRESS,
                "Wrong traits for Scientist"
            );
            require(msg.value == price, "Invalid price");
            require(remainingAmount >= 1, "Sold out");
            remainingAmount--;
            _create(to);
            uint256 tokenId = tokenIdCount.current();
            scientistTraits[tokenId] = traits;
            emit MintForGift(msg.sender, to, tokenId, block.timestamp);
        }
        function _create(address _account) internal {
            require(
                tokenIdCount.current() < MAX_MINTABLE,
                "Can not create more Scientist"
            );
            tokenIdCount.increment();
            uint256 tokenId = tokenIdCount.current();
            _mint(_account, tokenId);
            _addScientist(_account, tokenId);
            _setTokenRoyalty(tokenId, msg.sender, feeNumerator);
        }
        function ownerOf(uint256 tokenId)
            public
            view
            virtual
            override(ERC721Upgradeable, AScientistRepository)
            returns (address)
        {
            return ERC721Upgradeable.ownerOf(tokenId);
        }
        function addScientist(address account, uint256 tokenId)
            external
            override
            isOperator
        {
            _addScientist(account, tokenId);
        }
        function removeScientist(uint256 _tokenId, address _owner)
            external
            override
            isOperator
        {
            _removeScientist(_owner, _tokenId);
        }
        function updateScientist(
            uint256 tokenId,
            ScientistData.Scientist memory scientistData,
            address account
        ) external override isOperator {
            _updateScientist(tokenId, scientistData, account);
        }
        function withdrawETH(address payable to) external onlyTimelock {
            uint256 balance = address(this).balance;
            to.transfer(balance);
        }
        function supportsInterface(bytes4 interfaceId)
            public
            view
            virtual
            override(ERC721EnumerableUpgradeable, ERC2981Upgradeable)
            returns (bool)
        {
            return
                ERC721Upgradeable.supportsInterface(interfaceId) ||
                ERC2981Upgradeable.supportsInterface(interfaceId);
        }
        function setFeeNumerator(uint96 value) external onlyTimelock {
            feeNumerator = value;
        }
        function setIsCanTransfer(bool value) external onlyTimelock {
            isCanTransfer = value;
        }
        function name() public view virtual override returns (string memory) {
            return "MAD Metascientist";
        }
        function symbol() public view virtual override returns (string memory) {
            return "MMSCI";
        }
    }
    // SPDX-License-Identifier: GPL-3.0
    pragma solidity ^0.8.3;
    import "../../libs/ScientistData.sol";
    /**
     * @title Interface for interaction with particular scientist
     */
    interface IScientistRepository {
        event AddScientist(uint256 tokenId, ScientistData.Scientist scientist, uint256 timestamp);
        event UpdateScientist(
            uint256 tokenId,
            ScientistData.Scientist currentScientist,
            ScientistData.Scientist newScientist,
            uint256 timestamp
        );
        event RemoveScientist(uint256 _tokenId, ScientistData.Scientist _scientist, uint256 _timestamp);
        function addScientist(address _account, uint256 _tokenId) external;
        function removeScientist(uint256 _tokenId, address _owner) external;
        /**
         * @dev Returns meta scientist id's for particular user
         */
        function getUserMetascientistsIndexes(address _user)
            external
            view
            returns (uint256[] memory);
        function updateScientist(
            uint256 _tokenId,
            ScientistData.Scientist memory scientistData,
            address _account
        ) external;
        function getScientist(uint256 _tokenId)
            external
            view
            returns (ScientistData.Scientist memory);
    }
    // SPDX-License-Identifier: GPL-3.0
    pragma solidity ^0.8.3;
    interface IScientistCharacteristic {
        struct ScientistTraits {
            uint8 scientificField;
            uint8 personalityDisorders;
            Psychologicalforce psychologicalForce;
            uint8 vice;
            uint8 magnitudeOfStress;
        }
        struct Psychologicalforce {
            uint8 obedienceToAuthority;
            uint8 obedienceToConventions;
            uint8 tendencyTowardViolence;
        }
        //
        enum ScientificFields {
            ASTRO_PHYSICS,
            ATOMIC_CHEMISTRY,
            SPACE_TIME,
            HIVE_MIND,
            DARK_MATTER,
            BAUDRILLARD_THEORY
        }
        //
        enum PersonalityDisorders {
            PARANOID,
            SCHIZOID,
            AVOIDANT,
            OCD,
            NARCISSISTIC
        }
        enum Authority {
            TEDDY_BEAR,
            CAPTAIN_AMERICA,
            ROGUE,
            ANARCHIST,
            ANTICHRIST
        }
        enum Conventions {
            SIMP,
            DEGEN,
            GIGACHAD
        }
        enum Violence {
            PUSSY,
            THOUSAND_KICKS,
            G_SHIT,
            PSSSSYCHO,
            BERSERK,
            DNFWM
        }
        enum Vices {
            DRUNK,
            CYBERNETIC_AUGMENTATION_ADDICTION,
            INTERPLANETARY_SPACE_FUMES,
            TOAD_LICKER,
            SPINAL_FLUID_INSERTION,
            ELECTRICAL_SURGE_TREATMENT,
            MASOCHISM
        }
        enum MagnitudeOfStress {
            DIZNEE,
            CHILL,
            HMMM,
            EPISODIC,
            CHRONIC,
            HOLY_SHHHHT,
            BREAKEM
        }
    }// SPDX-License-Identifier: GPL-3.0
    pragma solidity ^0.8.3;
    import "@openzeppelin/contracts/utils/math/SafeMath.sol";
    import "@openzeppelin/contracts/utils/Multicall.sol";
    import "@openzeppelin/contracts/utils/Counters.sol";
    import "@openzeppelin/contracts/utils/structs/EnumerableSet.sol";
    import "../interfaces/IScientistRepository.sol";
    import "../../libs/ScientistData.sol";
    /**
     * @title Interface for interaction with particular scientist
     */
    abstract contract AScientistRepository is IScientistRepository, Multicall {
        using SafeMath for uint256;
        using Counters for Counters.Counter;
        //  are meta scientists
        mapping(uint256 => ScientistData.Scientist) scientists;
        mapping(address => uint256[]) private userIndexesArray;
        function _addScientist(address _account, uint256 _tokenId) internal {
            address _owner = ownerOf(_tokenId);
            require(_owner == _account, "Account is not the owner");
            userIndexesArray[_account].push(_tokenId);
    \t    emit AddScientist(_tokenId, scientists[_tokenId], block.timestamp);
        }
        function _removeScientist(address _account, uint256 _tokenId) internal {
            address _owner = ownerOf(_tokenId);
            require(_owner != address(0), "Token is not exists");
            require(_owner == _account, "Account is not the owner");
            uint256 indexInArray = _getIndexInScientistsArray(_account, _tokenId);
            require(indexInArray != type(uint256).max, "No such index");
            userIndexesArray[_account][indexInArray] = userIndexesArray[_account][userIndexesArray[_account].length - 1];
            userIndexesArray[_account].pop();
            emit RemoveScientist(_tokenId, scientists[_tokenId], block.timestamp);
        }
        function _getIndexInScientistsArray(address _user, uint256 _value)
            internal
            view
            returns (uint256)
        {
            for (uint256 i = 0; i < userIndexesArray[_user].length; i++) {
                if (userIndexesArray[_user][i] == _value) {
                    return i;
                }
            }
            return type(uint256).max;
        }
        /**
         * @dev Returns meta scientist id's for particular user
         */
        function getUserMetascientistsIndexes(address _user)
            external
            view
            override
            returns (uint256[] memory)
        {
            return userIndexesArray[_user];
        }
        function _updateScientist(
            uint256 _tokenId,
            ScientistData.Scientist memory _scientist,
            address _account
        ) internal {
            ScientistData.Scientist memory _oldscientist = scientists[_tokenId];
            require(_account != address(0), "Token not exists");
            require(_account == ownerOf(_tokenId), "wrong owner of Scientist");
            scientists[_tokenId] = _scientist;
            emit UpdateScientist(_tokenId, _oldscientist, _scientist, block.timestamp);
        }
        function getScientist(uint256 _tokenId)
            external
            view
            override
            returns (ScientistData.Scientist memory)
        {
            return scientists[_tokenId];
        }
        function ownerOf(uint256 tokenId) public view virtual returns (address);
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.0;
    /**
     * @title Representation of scientist with it fields
     */
    library ScientistData {
        /**
         *  Represents the basic parameters that describes scientist
         */
        struct Scientist {
            uint256 price;
            bool onSale;
            Point point;
        }
        struct Point {
            uint32 physics;
            uint32 chemistry;
            uint32 biology;
            uint32 sociology;
            uint32 mathematics;
        }
    }
    // SPDX-License-Identifier: GPL-3.0
    pragma solidity ^0.8.3;
    import "@openzeppelin/contracts/utils/structs/EnumerableSet.sol";
    /**
     * @title Interface to add alowed operator in additiona to owner
     */
    abstract contract IOperator {
        using EnumerableSet for EnumerableSet.AddressSet;
        EnumerableSet.AddressSet private operators;
        modifier isOperator() {
            require(operators.contains(msg.sender), "You do not have rights");
            _;
        }
        event OperatorAdded(address);
        event OperatorRemoved(address);
        function addOperator(address _operator) external virtual;
        function removeOperator(address _operator) external virtual;
        function _addOperator(address _operator) internal {
            require(_operator != address(0), "Address should not be empty");
            require(!operators.contains(_operator), "Already added");
            if (!operators.contains(_operator)) {
                operators.add(_operator);
                emit OperatorAdded(_operator);
            }
        }
        function _removeOperator(address _operator) internal {
            require(operators.contains(_operator), "Not exist");
            if (operators.contains(_operator)) {
                operators.remove(_operator);
                emit OperatorRemoved(_operator);
            }
        }
        function getOperators() external view returns (address[] memory) {
            return operators.values();
        }
    }
    // SPDX-License-Identifier: GPL-3.0
    pragma solidity ^0.8.3;
    abstract contract TimelockAccess {
        address public timelock;
        modifier onlyTimelock() {
            require(msg.sender == timelock, "Must call from Timelock");
            _;
        }
    }// SPDX-License-Identifier: MIT
    pragma solidity ^0.8.3;
    import {SafeMath} from "@openzeppelin/contracts/utils/math/SafeMath.sol";
    import {EIP712Base} from "./EIP712Base.sol";
    contract NativeMetaTransaction is EIP712Base {
        using SafeMath for uint256;
        bytes32 private constant META_TRANSACTION_TYPEHASH =
            keccak256(
                bytes(
                    "MetaTransaction(uint256 nonce,address from,bytes functionSignature)"
                )
            );
        event MetaTransactionExecuted(
            address userAddress,
            address payable relayerAddress,
            bytes functionSignature
        );
        mapping(address => uint256) private nonces;
        /*
         * Meta transaction structure.
         * No point of including value field here as if user is doing value transfer then he has the funds to pay for gas
         * He should call the desired function directly in that case.
         */
        struct MetaTransaction {
            uint256 nonce;
            address from;
            bytes functionSignature;
        }
        function executeMetaTransaction(
            address userAddress,
            bytes memory functionSignature,
            bytes32 sigR,
            bytes32 sigS,
            uint8 sigV
        ) public payable returns (bytes memory) {
            MetaTransaction memory metaTx = MetaTransaction({
                nonce: nonces[userAddress],
                from: userAddress,
                functionSignature: functionSignature
            });
            require(
                verify(userAddress, metaTx, sigR, sigS, sigV),
                "Signer and signature do not match"
            );
            // increase nonce for user (to avoid re-use)
            nonces[userAddress] = nonces[userAddress].add(1);
            emit MetaTransactionExecuted(
                userAddress,
                payable(msg.sender),
                functionSignature
            );
            // Append userAddress and relayer address at the end to extract it from calling context
            (bool success, bytes memory returnData) = address(this).call(
                abi.encodePacked(functionSignature, userAddress)
            );
            require(success, "Function call not successful");
            return returnData;
        }
        function hashMetaTransaction(MetaTransaction memory metaTx)
            internal
            pure
            returns (bytes32)
        {
            return
                keccak256(
                    abi.encode(
                        META_TRANSACTION_TYPEHASH,
                        metaTx.nonce,
                        metaTx.from,
                        keccak256(metaTx.functionSignature)
                    )
                );
        }
        function getNonce(address user) public view returns (uint256 nonce) {
            nonce = nonces[user];
        }
        function verify(
            address signer,
            MetaTransaction memory metaTx,
            bytes32 sigR,
            bytes32 sigS,
            uint8 sigV
        ) internal view returns (bool) {
            require(signer != address(0), "NativeMetaTransaction: INVALID_SIGNER");
            return
                signer ==
                ecrecover(
                    toTypedMessageHash(hashMetaTransaction(metaTx)),
                    sigV,
                    sigR,
                    sigS
                );
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.3;
    contract EIP712Base {
        struct EIP712Domain {
            string name;
            string version;
            address verifyingContract;
            bytes32 salt;
        }
        string public constant ERC712_VERSION = "1";
        bytes32 internal constant EIP712_DOMAIN_TYPEHASH =
            keccak256(
                bytes(
                    "EIP712Domain(string name,string version,address verifyingContract,bytes32 salt)"
                )
            );
        bytes32 internal domainSeparator;
        // supposed to be called once while initializing.
        // one of the contracts that inherits this contract follows proxy pattern
        // so it is not possible to do this in a constructor
        function _initializeEIP712(string memory name) internal {
            _setDomainSeparator(name);
        }
        function _setDomainSeparator(string memory name) internal {
            domainSeparator = keccak256(
                abi.encode(
                    EIP712_DOMAIN_TYPEHASH,
                    keccak256(bytes(name)),
                    keccak256(bytes(ERC712_VERSION)),
                    address(this),
                    bytes32(block.chainid)
                )
            );
        }
        function getdomainSeparator() public view returns (bytes32) {
            return domainSeparator;
        }
        /**
         * Accept message hash and returns hash message in EIP712 compatible form
         * So that it can be used to recover signer from signature signed using EIP712 formatted data
         * https://eips.ethereum.org/EIPS/eip-712
         * "\\\\x19" makes the encoding deterministic
         * "\\\\x01" is the version byte to make it compatible to EIP-191
         */
        function toTypedMessageHash(bytes32 messageHash)
            internal
            view
            returns (bytes32)
        {
            return
                keccak256(
                    abi.encodePacked("\\x19\\x01", getdomainSeparator(), messageHash)
                );
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.3;
    abstract contract ContextMixin {
        function msgSender() internal view returns (address payable sender) {
            if (msg.sender == address(this)) {
                bytes memory array = msg.data;
                uint256 index = msg.data.length;
                assembly {
                    // Load the 32 bytes word from memory with the address on the lower 20 bytes, and mask those.
                    sender := and(
                        mload(add(array, index)),
                        0xffffffffffffffffffffffffffffffffffffffff
                    )
                }
            } else {
                sender = payable(msg.sender);
            }
            return sender;
        }
    }
    // SPDX-License-Identifier: MIT
    pragma solidity ^0.8.3;
    import "@openzeppelin/contracts-upgradeable/token/ERC721/extensions/ERC721EnumerableUpgradeable.sol";
    import "@openzeppelin/contracts/utils/math/SafeMath.sol";
    import "@openzeppelin/contracts/utils/Strings.sol";
    import "./meta-transactions/ContentMixin.sol";
    import "./meta-transactions/NativeMetaTransaction.sol";
    import "../interfaces/IOperator.sol";
    import "../helpers/timelock-access/TimelockAccess.sol";
    contract OwnableDelegateProxy {}
    contract ProxyRegistry {
        mapping(address => OwnableDelegateProxy) public proxies;
    }
    /**
     * @title ERC721Tradable
     * ERC721Tradable - ERC721 contract that whitelists a trading address, and has minting functionality.
     */
    abstract contract ERC721TradableUpgradeable is
        ContextMixin,
        ERC721EnumerableUpgradeable,
        NativeMetaTransaction,
        TimelockAccess,
        IOperator
    {
        using SafeMath for uint256;
        function getProxyRegistryAddress() public virtual view returns (address);
        function burn(uint256 tokenId) external virtual {
            require(
                msg.sender == ownerOf(tokenId),
                "Caller is not owner of token id"
            );
            super._burn(tokenId);
        }
        /**
         * Override isApprovedForAll to whitelist user's OpenSea proxy accounts to enable gas-less listings.
         */
        function isApprovedForAll(address owner, address operator)
            public
            view
            override
            returns (bool)
        {
            // Whitelist OpenSea proxy contract for easy trading.
            ProxyRegistry proxyRegistry = ProxyRegistry(getProxyRegistryAddress());
            if (address(proxyRegistry.proxies(owner)) == operator) {
                return true;
            }
            return super.isApprovedForAll(owner, operator);
        }
        function addOperator(address _operator) external override onlyTimelock {
            _addOperator(_operator);
        }
        function removeOperator(address _operator) external override onlyTimelock {
            _removeOperator(_operator);
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.7.0) (utils/structs/EnumerableSet.sol)
    pragma solidity ^0.8.0;
    /**
     * @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.
     *
     * [WARNING]
     * ====
     *  Trying to delete such a structure from storage will likely result in data corruption, rendering the structure unusable.
     *  See https://github.com/ethereum/solidity/pull/11843[ethereum/solidity#11843] for more info.
     *
     *  In order to clean an EnumerableSet, you can either remove all elements one by one or create a fresh instance using an array of EnumerableSet.
     * ====
     */
    library EnumerableSet {
        // 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;
                if (lastIndex != toDeleteIndex) {
                    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] = valueIndex; // Replace lastValue's index to valueIndex
                }
                // 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) {
            return set._values[index];
        }
        /**
         * @dev Return the entire set in an array
         *
         * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
         * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
         * this function has an unbounded cost, and using it as part of a state-changing function may render the function
         * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
         */
        function _values(Set storage set) private view returns (bytes32[] memory) {
            return set._values;
        }
        // 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);
        }
        /**
         * @dev Return the entire set in an array
         *
         * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
         * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
         * this function has an unbounded cost, and using it as part of a state-changing function may render the function
         * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
         */
        function values(Bytes32Set storage set) internal view returns (bytes32[] memory) {
            return _values(set._inner);
        }
        // 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))));
        }
        /**
         * @dev Return the entire set in an array
         *
         * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
         * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
         * this function has an unbounded cost, and using it as part of a state-changing function may render the function
         * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
         */
        function values(AddressSet storage set) internal view returns (address[] memory) {
            bytes32[] memory store = _values(set._inner);
            address[] memory result;
            /// @solidity memory-safe-assembly
            assembly {
                result := store
            }
            return result;
        }
        // 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));
        }
        /**
         * @dev Return the entire set in an array
         *
         * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
         * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
         * this function has an unbounded cost, and using it as part of a state-changing function may render the function
         * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
         */
        function values(UintSet storage set) internal view returns (uint256[] memory) {
            bytes32[] memory store = _values(set._inner);
            uint256[] memory result;
            /// @solidity memory-safe-assembly
            assembly {
                result := store
            }
            return result;
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.6.0) (utils/math/SafeMath.sol)
    pragma solidity ^0.8.0;
    // CAUTION
    // This version of SafeMath should only be used with Solidity 0.8 or later,
    // because it relies on the compiler's built in overflow checks.
    /**
     * @dev Wrappers over Solidity's arithmetic operations.
     *
     * NOTE: `SafeMath` is generally not needed starting with Solidity 0.8, since the compiler
     * now has built in overflow checking.
     */
    library SafeMath {
        /**
         * @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) {
            unchecked {
                uint256 c = a + b;
                if (c < a) return (false, 0);
                return (true, c);
            }
        }
        /**
         * @dev Returns the subtraction of two unsigned integers, with an overflow flag.
         *
         * _Available since v3.4._
         */
        function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
            unchecked {
                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) {
            unchecked {
                // 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) {
            unchecked {
                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) {
            unchecked {
                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) {
            return a + b;
        }
        /**
         * @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) {
            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) {
            return a * b;
        }
        /**
         * @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.
         *
         * Requirements:
         *
         * - The divisor cannot be zero.
         */
        function div(uint256 a, uint256 b) internal pure returns (uint256) {
            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) {
            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) {
            unchecked {
                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.
         *
         * 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) {
            unchecked {
                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) {
            unchecked {
                require(b > 0, errorMessage);
                return a % b;
            }
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.7.3) (utils/cryptography/ECDSA.sol)
    pragma solidity ^0.8.0;
    import "../Strings.sol";
    /**
     * @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 {
        enum RecoverError {
            NoError,
            InvalidSignature,
            InvalidSignatureLength,
            InvalidSignatureS,
            InvalidSignatureV
        }
        function _throwError(RecoverError error) private pure {
            if (error == RecoverError.NoError) {
                return; // no error: do nothing
            } else if (error == RecoverError.InvalidSignature) {
                revert("ECDSA: invalid signature");
            } else if (error == RecoverError.InvalidSignatureLength) {
                revert("ECDSA: invalid signature length");
            } else if (error == RecoverError.InvalidSignatureS) {
                revert("ECDSA: invalid signature 's' value");
            } else if (error == RecoverError.InvalidSignatureV) {
                revert("ECDSA: invalid signature 'v' value");
            }
        }
        /**
         * @dev Returns the address that signed a hashed message (`hash`) with
         * `signature` or error string. 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.
         *
         * Documentation for signature generation:
         * - with https://web3js.readthedocs.io/en/v1.3.4/web3-eth-accounts.html#sign[Web3.js]
         * - with https://docs.ethers.io/v5/api/signer/#Signer-signMessage[ethers]
         *
         * _Available since v4.3._
         */
        function tryRecover(bytes32 hash, bytes memory signature) internal pure returns (address, RecoverError) {
            if (signature.length == 65) {
                bytes32 r;
                bytes32 s;
                uint8 v;
                // ecrecover takes the signature parameters, and the only way to get them
                // currently is to use assembly.
                /// @solidity memory-safe-assembly
                assembly {
                    r := mload(add(signature, 0x20))
                    s := mload(add(signature, 0x40))
                    v := byte(0, mload(add(signature, 0x60)))
                }
                return tryRecover(hash, v, r, s);
            } else {
                return (address(0), RecoverError.InvalidSignatureLength);
            }
        }
        /**
         * @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) {
            (address recovered, RecoverError error) = tryRecover(hash, signature);
            _throwError(error);
            return recovered;
        }
        /**
         * @dev Overload of {ECDSA-tryRecover} that receives the `r` and `vs` short-signature fields separately.
         *
         * See https://eips.ethereum.org/EIPS/eip-2098[EIP-2098 short signatures]
         *
         * _Available since v4.3._
         */
        function tryRecover(
            bytes32 hash,
            bytes32 r,
            bytes32 vs
        ) internal pure returns (address, RecoverError) {
            bytes32 s = vs & bytes32(0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff);
            uint8 v = uint8((uint256(vs) >> 255) + 27);
            return tryRecover(hash, v, r, s);
        }
        /**
         * @dev Overload of {ECDSA-recover} that receives the `r and `vs` short-signature fields separately.
         *
         * _Available since v4.2._
         */
        function recover(
            bytes32 hash,
            bytes32 r,
            bytes32 vs
        ) internal pure returns (address) {
            (address recovered, RecoverError error) = tryRecover(hash, r, vs);
            _throwError(error);
            return recovered;
        }
        /**
         * @dev Overload of {ECDSA-tryRecover} that receives the `v`,
         * `r` and `s` signature fields separately.
         *
         * _Available since v4.3._
         */
        function tryRecover(
            bytes32 hash,
            uint8 v,
            bytes32 r,
            bytes32 s
        ) internal pure returns (address, RecoverError) {
            // 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 (301): 0 < s < secp256k1n ÷ 2 + 1, and for v in (302): 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.
            if (uint256(s) > 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0) {
                return (address(0), RecoverError.InvalidSignatureS);
            }
            if (v != 27 && v != 28) {
                return (address(0), RecoverError.InvalidSignatureV);
            }
            // If the signature is valid (and not malleable), return the signer address
            address signer = ecrecover(hash, v, r, s);
            if (signer == address(0)) {
                return (address(0), RecoverError.InvalidSignature);
            }
            return (signer, RecoverError.NoError);
        }
        /**
         * @dev Overload of {ECDSA-recover} that receives the `v`,
         * `r` and `s` signature fields separately.
         */
        function recover(
            bytes32 hash,
            uint8 v,
            bytes32 r,
            bytes32 s
        ) internal pure returns (address) {
            (address recovered, RecoverError error) = tryRecover(hash, v, r, s);
            _throwError(error);
            return recovered;
        }
        /**
         * @dev Returns an Ethereum Signed Message, created from a `hash`. This
         * produces hash corresponding to the one signed with the
         * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
         * JSON-RPC method as part of EIP-191.
         *
         * 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));
        }
        /**
         * @dev Returns an Ethereum Signed Message, created from `s`. This
         * produces hash corresponding to the one signed with the
         * https://eth.wiki/json-rpc/API#eth_sign[`eth_sign`]
         * JSON-RPC method as part of EIP-191.
         *
         * See {recover}.
         */
        function toEthSignedMessageHash(bytes memory s) internal pure returns (bytes32) {
            return keccak256(abi.encodePacked("\\x19Ethereum Signed Message:\
    ", Strings.toString(s.length), s));
        }
        /**
         * @dev Returns an Ethereum Signed Typed Data, created from a
         * `domainSeparator` and a `structHash`. This produces hash corresponding
         * to the one signed with the
         * https://eips.ethereum.org/EIPS/eip-712[`eth_signTypedData`]
         * JSON-RPC method as part of EIP-712.
         *
         * See {recover}.
         */
        function toTypedDataHash(bytes32 domainSeparator, bytes32 structHash) internal pure returns (bytes32) {
            return keccak256(abi.encodePacked("\\x19\\x01", domainSeparator, structHash));
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.7.0) (utils/Strings.sol)
    pragma solidity ^0.8.0;
    /**
     * @dev String operations.
     */
    library Strings {
        bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
        uint8 private constant _ADDRESS_LENGTH = 20;
        /**
         * @dev Converts a `uint256` to its ASCII `string` decimal 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);
            while (value != 0) {
                digits -= 1;
                buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
                value /= 10;
            }
            return string(buffer);
        }
        /**
         * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
         */
        function toHexString(uint256 value) internal pure returns (string memory) {
            if (value == 0) {
                return "0x00";
            }
            uint256 temp = value;
            uint256 length = 0;
            while (temp != 0) {
                length++;
                temp >>= 8;
            }
            return toHexString(value, length);
        }
        /**
         * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
         */
        function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
            bytes memory buffer = new bytes(2 * length + 2);
            buffer[0] = "0";
            buffer[1] = "x";
            for (uint256 i = 2 * length + 1; i > 1; --i) {
                buffer[i] = _HEX_SYMBOLS[value & 0xf];
                value >>= 4;
            }
            require(value == 0, "Strings: hex length insufficient");
            return string(buffer);
        }
        /**
         * @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
         */
        function toHexString(address addr) internal pure returns (string memory) {
            return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.5.0) (utils/Multicall.sol)
    pragma solidity ^0.8.0;
    import "./Address.sol";
    /**
     * @dev Provides a function to batch together multiple calls in a single external call.
     *
     * _Available since v4.1._
     */
    abstract contract Multicall {
        /**
         * @dev Receives and executes a batch of function calls on this contract.
         */
        function multicall(bytes[] calldata data) external virtual returns (bytes[] memory results) {
            results = new bytes[](data.length);
            for (uint256 i = 0; i < data.length; i++) {
                results[i] = Address.functionDelegateCall(address(this), data[i]);
            }
            return results;
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (utils/Counters.sol)
    pragma solidity ^0.8.0;
    /**
     * @title Counters
     * @author Matt Condon (@shrugs)
     * @dev Provides counters that can only be incremented, decremented or reset. This can be used e.g. to track the number
     * of elements in a mapping, issuing ERC721 ids, or counting request ids.
     *
     * Include with `using Counters for Counters.Counter;`
     */
    library Counters {
        struct Counter {
            // This variable should never be directly accessed by users of the library: interactions must be restricted to
            // the library's function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add
            // this feature: see https://github.com/ethereum/solidity/issues/4637
            uint256 _value; // default: 0
        }
        function current(Counter storage counter) internal view returns (uint256) {
            return counter._value;
        }
        function increment(Counter storage counter) internal {
            unchecked {
                counter._value += 1;
            }
        }
        function decrement(Counter storage counter) internal {
            uint256 value = counter._value;
            require(value > 0, "Counter: decrement overflow");
            unchecked {
                counter._value = value - 1;
            }
        }
        function reset(Counter storage counter) internal {
            counter._value = 0;
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.7.0) (utils/Address.sol)
    pragma solidity ^0.8.1;
    /**
     * @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
         * ====
         *
         * [IMPORTANT]
         * ====
         * You shouldn't rely on `isContract` to protect against flash loan attacks!
         *
         * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
         * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
         * constructor.
         * ====
         */
        function isContract(address account) internal view returns (bool) {
            // This method relies on extcodesize/address.code.length, which returns 0
            // for contracts in construction, since the code is only stored at the end
            // of the constructor execution.
            return account.code.length > 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");
            (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");
            (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");
            (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");
            (bool success, bytes memory returndata) = target.delegatecall(data);
            return verifyCallResult(success, returndata, errorMessage);
        }
        /**
         * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
         * revert reason using the provided one.
         *
         * _Available since v4.3._
         */
        function verifyCallResult(
            bool success,
            bytes memory returndata,
            string memory errorMessage
        ) internal 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
                    /// @solidity memory-safe-assembly
                    assembly {
                        let returndata_size := mload(returndata)
                        revert(add(32, returndata), returndata_size)
                    }
                } else {
                    revert(errorMessage);
                }
            }
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
    pragma solidity ^0.8.0;
    /**
     * @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
    // OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)
    pragma solidity ^0.8.0;
    import "./IERC165Upgradeable.sol";
    import "../../proxy/utils/Initializable.sol";
    /**
     * @dev Implementation of the {IERC165} interface.
     *
     * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
     * for the additional interface id that will be supported. For example:
     *
     * ```solidity
     * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
     *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
     * }
     * ```
     *
     * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
     */
    abstract contract ERC165Upgradeable is Initializable, IERC165Upgradeable {
        function __ERC165_init() internal onlyInitializing {
        }
        function __ERC165_init_unchained() internal onlyInitializing {
        }
        /**
         * @dev See {IERC165-supportsInterface}.
         */
        function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
            return interfaceId == type(IERC165Upgradeable).interfaceId;
        }
        /**
         * @dev This empty reserved space is put in place to allow future versions to add new
         * variables without shifting down storage in the inheritance chain.
         * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
         */
        uint256[50] private __gap;
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.7.0) (utils/Strings.sol)
    pragma solidity ^0.8.0;
    /**
     * @dev String operations.
     */
    library StringsUpgradeable {
        bytes16 private constant _HEX_SYMBOLS = "0123456789abcdef";
        uint8 private constant _ADDRESS_LENGTH = 20;
        /**
         * @dev Converts a `uint256` to its ASCII `string` decimal 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);
            while (value != 0) {
                digits -= 1;
                buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
                value /= 10;
            }
            return string(buffer);
        }
        /**
         * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation.
         */
        function toHexString(uint256 value) internal pure returns (string memory) {
            if (value == 0) {
                return "0x00";
            }
            uint256 temp = value;
            uint256 length = 0;
            while (temp != 0) {
                length++;
                temp >>= 8;
            }
            return toHexString(value, length);
        }
        /**
         * @dev Converts a `uint256` to its ASCII `string` hexadecimal representation with fixed length.
         */
        function toHexString(uint256 value, uint256 length) internal pure returns (string memory) {
            bytes memory buffer = new bytes(2 * length + 2);
            buffer[0] = "0";
            buffer[1] = "x";
            for (uint256 i = 2 * length + 1; i > 1; --i) {
                buffer[i] = _HEX_SYMBOLS[value & 0xf];
                value >>= 4;
            }
            require(value == 0, "Strings: hex length insufficient");
            return string(buffer);
        }
        /**
         * @dev Converts an `address` with fixed length of 20 bytes to its not checksummed ASCII `string` hexadecimal representation.
         */
        function toHexString(address addr) internal pure returns (string memory) {
            return toHexString(uint256(uint160(addr)), _ADDRESS_LENGTH);
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
    pragma solidity ^0.8.0;
    import "../proxy/utils/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 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 onlyInitializing {
        }
        function __Context_init_unchained() internal onlyInitializing {
        }
        function _msgSender() internal view virtual returns (address) {
            return msg.sender;
        }
        function _msgData() internal view virtual returns (bytes calldata) {
            return msg.data;
        }
        /**
         * @dev This empty reserved space is put in place to allow future versions to add new
         * variables without shifting down storage in the inheritance chain.
         * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
         */
        uint256[50] private __gap;
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.7.0) (utils/Address.sol)
    pragma solidity ^0.8.1;
    /**
     * @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
         * ====
         *
         * [IMPORTANT]
         * ====
         * You shouldn't rely on `isContract` to protect against flash loan attacks!
         *
         * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
         * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
         * constructor.
         * ====
         */
        function isContract(address account) internal view returns (bool) {
            // This method relies on extcodesize/address.code.length, which returns 0
            // for contracts in construction, since the code is only stored at the end
            // of the constructor execution.
            return account.code.length > 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");
            (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");
            (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");
            (bool success, bytes memory returndata) = target.staticcall(data);
            return verifyCallResult(success, returndata, errorMessage);
        }
        /**
         * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
         * revert reason using the provided one.
         *
         * _Available since v4.3._
         */
        function verifyCallResult(
            bool success,
            bytes memory returndata,
            string memory errorMessage
        ) internal 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
                    /// @solidity memory-safe-assembly
                    assembly {
                        let returndata_size := mload(returndata)
                        revert(add(32, returndata), returndata_size)
                    }
                } else {
                    revert(errorMessage);
                }
            }
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.7.0) (token/common/ERC2981.sol)
    pragma solidity ^0.8.0;
    import "../../interfaces/IERC2981Upgradeable.sol";
    import "../../utils/introspection/ERC165Upgradeable.sol";
    import "../../proxy/utils/Initializable.sol";
    /**
     * @dev Implementation of the NFT Royalty Standard, a standardized way to retrieve royalty payment information.
     *
     * Royalty information can be specified globally for all token ids via {_setDefaultRoyalty}, and/or individually for
     * specific token ids via {_setTokenRoyalty}. The latter takes precedence over the first.
     *
     * Royalty is specified as a fraction of sale price. {_feeDenominator} is overridable but defaults to 10000, meaning the
     * fee is specified in basis points by default.
     *
     * IMPORTANT: ERC-2981 only specifies a way to signal royalty information and does not enforce its payment. See
     * https://eips.ethereum.org/EIPS/eip-2981#optional-royalty-payments[Rationale] in the EIP. Marketplaces are expected to
     * voluntarily pay royalties together with sales, but note that this standard is not yet widely supported.
     *
     * _Available since v4.5._
     */
    abstract contract ERC2981Upgradeable is Initializable, IERC2981Upgradeable, ERC165Upgradeable {
        function __ERC2981_init() internal onlyInitializing {
        }
        function __ERC2981_init_unchained() internal onlyInitializing {
        }
        struct RoyaltyInfo {
            address receiver;
            uint96 royaltyFraction;
        }
        RoyaltyInfo private _defaultRoyaltyInfo;
        mapping(uint256 => RoyaltyInfo) private _tokenRoyaltyInfo;
        /**
         * @dev See {IERC165-supportsInterface}.
         */
        function supportsInterface(bytes4 interfaceId) public view virtual override(IERC165Upgradeable, ERC165Upgradeable) returns (bool) {
            return interfaceId == type(IERC2981Upgradeable).interfaceId || super.supportsInterface(interfaceId);
        }
        /**
         * @inheritdoc IERC2981Upgradeable
         */
        function royaltyInfo(uint256 _tokenId, uint256 _salePrice) public view virtual override returns (address, uint256) {
            RoyaltyInfo memory royalty = _tokenRoyaltyInfo[_tokenId];
            if (royalty.receiver == address(0)) {
                royalty = _defaultRoyaltyInfo;
            }
            uint256 royaltyAmount = (_salePrice * royalty.royaltyFraction) / _feeDenominator();
            return (royalty.receiver, royaltyAmount);
        }
        /**
         * @dev The denominator with which to interpret the fee set in {_setTokenRoyalty} and {_setDefaultRoyalty} as a
         * fraction of the sale price. Defaults to 10000 so fees are expressed in basis points, but may be customized by an
         * override.
         */
        function _feeDenominator() internal pure virtual returns (uint96) {
            return 10000;
        }
        /**
         * @dev Sets the royalty information that all ids in this contract will default to.
         *
         * Requirements:
         *
         * - `receiver` cannot be the zero address.
         * - `feeNumerator` cannot be greater than the fee denominator.
         */
        function _setDefaultRoyalty(address receiver, uint96 feeNumerator) internal virtual {
            require(feeNumerator <= _feeDenominator(), "ERC2981: royalty fee will exceed salePrice");
            require(receiver != address(0), "ERC2981: invalid receiver");
            _defaultRoyaltyInfo = RoyaltyInfo(receiver, feeNumerator);
        }
        /**
         * @dev Removes default royalty information.
         */
        function _deleteDefaultRoyalty() internal virtual {
            delete _defaultRoyaltyInfo;
        }
        /**
         * @dev Sets the royalty information for a specific token id, overriding the global default.
         *
         * Requirements:
         *
         * - `receiver` cannot be the zero address.
         * - `feeNumerator` cannot be greater than the fee denominator.
         */
        function _setTokenRoyalty(
            uint256 tokenId,
            address receiver,
            uint96 feeNumerator
        ) internal virtual {
            require(feeNumerator <= _feeDenominator(), "ERC2981: royalty fee will exceed salePrice");
            require(receiver != address(0), "ERC2981: Invalid parameters");
            _tokenRoyaltyInfo[tokenId] = RoyaltyInfo(receiver, feeNumerator);
        }
        /**
         * @dev Resets royalty information for the token id back to the global default.
         */
        function _resetTokenRoyalty(uint256 tokenId) internal virtual {
            delete _tokenRoyaltyInfo[tokenId];
        }
        /**
         * @dev This empty reserved space is put in place to allow future versions to add new
         * variables without shifting down storage in the inheritance chain.
         * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
         */
        uint256[48] private __gap;
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/IERC721Metadata.sol)
    pragma solidity ^0.8.0;
    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
    // OpenZeppelin Contracts (last updated v4.5.0) (token/ERC721/extensions/IERC721Enumerable.sol)
    pragma solidity ^0.8.0;
    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);
        /**
         * @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
    // OpenZeppelin Contracts v4.4.1 (token/ERC721/extensions/ERC721Enumerable.sol)
    pragma solidity ^0.8.0;
    import "../ERC721Upgradeable.sol";
    import "./IERC721EnumerableUpgradeable.sol";
    import "../../../proxy/utils/Initializable.sol";
    /**
     * @dev This implements an optional extension of {ERC721} defined in the EIP that adds
     * enumerability of all the token ids in the contract as well as all token ids owned by each
     * account.
     */
    abstract contract ERC721EnumerableUpgradeable is Initializable, ERC721Upgradeable, IERC721EnumerableUpgradeable {
        function __ERC721Enumerable_init() internal onlyInitializing {
        }
        function __ERC721Enumerable_init_unchained() internal onlyInitializing {
        }
        // Mapping from owner to list of owned token IDs
        mapping(address => mapping(uint256 => uint256)) private _ownedTokens;
        // Mapping from token ID to index of the owner tokens list
        mapping(uint256 => uint256) private _ownedTokensIndex;
        // Array with all token ids, used for enumeration
        uint256[] private _allTokens;
        // Mapping from token id to position in the allTokens array
        mapping(uint256 => uint256) private _allTokensIndex;
        /**
         * @dev See {IERC165-supportsInterface}.
         */
        function supportsInterface(bytes4 interfaceId) public view virtual override(IERC165Upgradeable, ERC721Upgradeable) returns (bool) {
            return interfaceId == type(IERC721EnumerableUpgradeable).interfaceId || super.supportsInterface(interfaceId);
        }
        /**
         * @dev See {IERC721Enumerable-tokenOfOwnerByIndex}.
         */
        function tokenOfOwnerByIndex(address owner, uint256 index) public view virtual override returns (uint256) {
            require(index < ERC721Upgradeable.balanceOf(owner), "ERC721Enumerable: owner index out of bounds");
            return _ownedTokens[owner][index];
        }
        /**
         * @dev See {IERC721Enumerable-totalSupply}.
         */
        function totalSupply() public view virtual override returns (uint256) {
            return _allTokens.length;
        }
        /**
         * @dev See {IERC721Enumerable-tokenByIndex}.
         */
        function tokenByIndex(uint256 index) public view virtual override returns (uint256) {
            require(index < ERC721EnumerableUpgradeable.totalSupply(), "ERC721Enumerable: global index out of bounds");
            return _allTokens[index];
        }
        /**
         * @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 override {
            super._beforeTokenTransfer(from, to, tokenId);
            if (from == address(0)) {
                _addTokenToAllTokensEnumeration(tokenId);
            } else if (from != to) {
                _removeTokenFromOwnerEnumeration(from, tokenId);
            }
            if (to == address(0)) {
                _removeTokenFromAllTokensEnumeration(tokenId);
            } else if (to != from) {
                _addTokenToOwnerEnumeration(to, tokenId);
            }
        }
        /**
         * @dev Private function to add a token to this extension's ownership-tracking data structures.
         * @param to address representing the new owner of the given token ID
         * @param tokenId uint256 ID of the token to be added to the tokens list of the given address
         */
        function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {
            uint256 length = ERC721Upgradeable.balanceOf(to);
            _ownedTokens[to][length] = tokenId;
            _ownedTokensIndex[tokenId] = length;
        }
        /**
         * @dev Private function to add a token to this extension's token tracking data structures.
         * @param tokenId uint256 ID of the token to be added to the tokens list
         */
        function _addTokenToAllTokensEnumeration(uint256 tokenId) private {
            _allTokensIndex[tokenId] = _allTokens.length;
            _allTokens.push(tokenId);
        }
        /**
         * @dev Private function to remove a token from this extension's ownership-tracking data structures. Note that
         * while the token is not assigned a new owner, the `_ownedTokensIndex` mapping is _not_ updated: this allows for
         * gas optimizations e.g. when performing a transfer operation (avoiding double writes).
         * This has O(1) time complexity, but alters the order of the _ownedTokens array.
         * @param from address representing the previous owner of the given token ID
         * @param tokenId uint256 ID of the token to be removed from the tokens list of the given address
         */
        function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {
            // To prevent a gap in from's tokens array, we store the last token in the index of the token to delete, and
            // then delete the last slot (swap and pop).
            uint256 lastTokenIndex = ERC721Upgradeable.balanceOf(from) - 1;
            uint256 tokenIndex = _ownedTokensIndex[tokenId];
            // When the token to delete is the last token, the swap operation is unnecessary
            if (tokenIndex != lastTokenIndex) {
                uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];
                _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
                _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
            }
            // This also deletes the contents at the last position of the array
            delete _ownedTokensIndex[tokenId];
            delete _ownedTokens[from][lastTokenIndex];
        }
        /**
         * @dev Private function to remove a token from this extension's token tracking data structures.
         * This has O(1) time complexity, but alters the order of the _allTokens array.
         * @param tokenId uint256 ID of the token to be removed from the tokens list
         */
        function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {
            // To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and
            // then delete the last slot (swap and pop).
            uint256 lastTokenIndex = _allTokens.length - 1;
            uint256 tokenIndex = _allTokensIndex[tokenId];
            // When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so
            // rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding
            // an 'if' statement (like in _removeTokenFromOwnerEnumeration)
            uint256 lastTokenId = _allTokens[lastTokenIndex];
            _allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
            _allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token's index
            // This also deletes the contents at the last position of the array
            delete _allTokensIndex[tokenId];
            _allTokens.pop();
        }
        /**
         * @dev This empty reserved space is put in place to allow future versions to add new
         * variables without shifting down storage in the inheritance chain.
         * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
         */
        uint256[46] private __gap;
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.7.0) (token/ERC721/IERC721.sol)
    pragma solidity ^0.8.0;
    import "../../utils/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`.
         *
         * 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;
        /**
         * @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 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 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 the account approved for `tokenId` token.
         *
         * Requirements:
         *
         * - `tokenId` must exist.
         */
        function getApproved(uint256 tokenId) external view returns (address operator);
        /**
         * @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);
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.6.0) (token/ERC721/IERC721Receiver.sol)
    pragma solidity ^0.8.0;
    /**
     * @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 `IERC721Receiver.onERC721Received.selector`.
         */
        function onERC721Received(
            address operator,
            address from,
            uint256 tokenId,
            bytes calldata data
        ) external returns (bytes4);
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.7.0) (token/ERC721/ERC721.sol)
    pragma solidity ^0.8.0;
    import "./IERC721Upgradeable.sol";
    import "./IERC721ReceiverUpgradeable.sol";
    import "./extensions/IERC721MetadataUpgradeable.sol";
    import "../../utils/AddressUpgradeable.sol";
    import "../../utils/ContextUpgradeable.sol";
    import "../../utils/StringsUpgradeable.sol";
    import "../../utils/introspection/ERC165Upgradeable.sol";
    import "../../proxy/utils/Initializable.sol";
    /**
     * @dev Implementation of https://eips.ethereum.org/EIPS/eip-721[ERC721] Non-Fungible Token Standard, including
     * the Metadata extension, but not including the Enumerable extension, which is available separately as
     * {ERC721Enumerable}.
     */
    contract ERC721Upgradeable is Initializable, ContextUpgradeable, ERC165Upgradeable, IERC721Upgradeable, IERC721MetadataUpgradeable {
        using AddressUpgradeable for address;
        using StringsUpgradeable for uint256;
        // Token name
        string private _name;
        // Token symbol
        string private _symbol;
        // Mapping from token ID to owner address
        mapping(uint256 => address) private _owners;
        // Mapping owner address to token count
        mapping(address => uint256) private _balances;
        // 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;
        /**
         * @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 onlyInitializing {
            __ERC721_init_unchained(name_, symbol_);
        }
        function __ERC721_init_unchained(string memory name_, string memory symbol_) internal onlyInitializing {
            _name = name_;
            _symbol = symbol_;
        }
        /**
         * @dev See {IERC165-supportsInterface}.
         */
        function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165Upgradeable, IERC165Upgradeable) returns (bool) {
            return
                interfaceId == type(IERC721Upgradeable).interfaceId ||
                interfaceId == type(IERC721MetadataUpgradeable).interfaceId ||
                super.supportsInterface(interfaceId);
        }
        /**
         * @dev See {IERC721-balanceOf}.
         */
        function balanceOf(address owner) public view virtual override returns (uint256) {
            require(owner != address(0), "ERC721: address zero is not a valid owner");
            return _balances[owner];
        }
        /**
         * @dev See {IERC721-ownerOf}.
         */
        function ownerOf(uint256 tokenId) public view virtual override returns (address) {
            address owner = _owners[tokenId];
            require(owner != address(0), "ERC721: invalid token ID");
            return owner;
        }
        /**
         * @dev See {IERC721Metadata-name}.
         */
        function name() public view virtual override returns (string memory) {
            return _name;
        }
        /**
         * @dev See {IERC721Metadata-symbol}.
         */
        function symbol() public view virtual override returns (string memory) {
            return _symbol;
        }
        /**
         * @dev See {IERC721Metadata-tokenURI}.
         */
        function tokenURI(uint256 tokenId) public view virtual override returns (string memory) {
            _requireMinted(tokenId);
            string memory baseURI = _baseURI();
            return bytes(baseURI).length > 0 ? string(abi.encodePacked(baseURI, tokenId.toString())) : "";
        }
        /**
         * @dev Base URI for computing {tokenURI}. If set, the resulting URI for each
         * token will be the concatenation of the `baseURI` and the `tokenId`. Empty
         * by default, can be overridden in child contracts.
         */
        function _baseURI() internal view virtual returns (string memory) {
            return "";
        }
        /**
         * @dev See {IERC721-approve}.
         */
        function approve(address to, uint256 tokenId) public virtual override {
            address owner = ERC721Upgradeable.ownerOf(tokenId);
            require(to != owner, "ERC721: approval to current owner");
            require(
                _msgSender() == owner || isApprovedForAll(owner, _msgSender()),
                "ERC721: approve caller is not token owner nor approved for all"
            );
            _approve(to, tokenId);
        }
        /**
         * @dev See {IERC721-getApproved}.
         */
        function getApproved(uint256 tokenId) public view virtual override returns (address) {
            _requireMinted(tokenId);
            return _tokenApprovals[tokenId];
        }
        /**
         * @dev See {IERC721-setApprovalForAll}.
         */
        function setApprovalForAll(address operator, bool approved) public virtual override {
            _setApprovalForAll(_msgSender(), operator, approved);
        }
        /**
         * @dev See {IERC721-isApprovedForAll}.
         */
        function isApprovedForAll(address owner, address operator) public view virtual 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: caller is not token 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: caller is not token 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 virtual returns (bool) {
            return _owners[tokenId] != address(0);
        }
        /**
         * @dev Returns whether `spender` is allowed to manage `tokenId`.
         *
         * Requirements:
         *
         * - `tokenId` must exist.
         */
        function _isApprovedOrOwner(address spender, uint256 tokenId) internal view virtual returns (bool) {
            address owner = ERC721Upgradeable.ownerOf(tokenId);
            return (spender == owner || isApprovedForAll(owner, spender) || getApproved(tokenId) == spender);
        }
        /**
         * @dev Safely mints `tokenId` and transfers it to `to`.
         *
         * Requirements:
         *
         * - `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);
            _balances[to] += 1;
            _owners[tokenId] = to;
            emit Transfer(address(0), to, tokenId);
            _afterTokenTransfer(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 = ERC721Upgradeable.ownerOf(tokenId);
            _beforeTokenTransfer(owner, address(0), tokenId);
            // Clear approvals
            _approve(address(0), tokenId);
            _balances[owner] -= 1;
            delete _owners[tokenId];
            emit Transfer(owner, address(0), tokenId);
            _afterTokenTransfer(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(ERC721Upgradeable.ownerOf(tokenId) == from, "ERC721: transfer from incorrect owner");
            require(to != address(0), "ERC721: transfer to the zero address");
            _beforeTokenTransfer(from, to, tokenId);
            // Clear approvals from the previous owner
            _approve(address(0), tokenId);
            _balances[from] -= 1;
            _balances[to] += 1;
            _owners[tokenId] = to;
            emit Transfer(from, to, tokenId);
            _afterTokenTransfer(from, to, tokenId);
        }
        /**
         * @dev Approve `to` to operate on `tokenId`
         *
         * Emits an {Approval} event.
         */
        function _approve(address to, uint256 tokenId) internal virtual {
            _tokenApprovals[tokenId] = to;
            emit Approval(ERC721Upgradeable.ownerOf(tokenId), to, tokenId);
        }
        /**
         * @dev Approve `operator` to operate on all of `owner` tokens
         *
         * Emits an {ApprovalForAll} event.
         */
        function _setApprovalForAll(
            address owner,
            address operator,
            bool approved
        ) internal virtual {
            require(owner != operator, "ERC721: approve to caller");
            _operatorApprovals[owner][operator] = approved;
            emit ApprovalForAll(owner, operator, approved);
        }
        /**
         * @dev Reverts if the `tokenId` has not been minted yet.
         */
        function _requireMinted(uint256 tokenId) internal view virtual {
            require(_exists(tokenId), "ERC721: invalid token ID");
        }
        /**
         * @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()) {
                try IERC721ReceiverUpgradeable(to).onERC721Received(_msgSender(), from, tokenId, data) returns (bytes4 retval) {
                    return retval == IERC721ReceiverUpgradeable.onERC721Received.selector;
                } catch (bytes memory reason) {
                    if (reason.length == 0) {
                        revert("ERC721: transfer to non ERC721Receiver implementer");
                    } else {
                        /// @solidity memory-safe-assembly
                        assembly {
                            revert(add(32, reason), mload(reason))
                        }
                    }
                }
            } else {
                return true;
            }
        }
        /**
         * @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` and `to` are never both zero.
         *
         * 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 {}
        /**
         * @dev Hook that is called after any transfer of tokens. This includes
         * minting and burning.
         *
         * Calling conditions:
         *
         * - when `from` and `to` are both non-zero.
         * - `from` and `to` are never both zero.
         *
         * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
         */
        function _afterTokenTransfer(
            address from,
            address to,
            uint256 tokenId
        ) internal virtual {}
        /**
         * @dev This empty reserved space is put in place to allow future versions to add new
         * variables without shifting down storage in the inheritance chain.
         * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
         */
        uint256[44] private __gap;
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts v4.4.1 (security/ReentrancyGuard.sol)
    pragma solidity ^0.8.0;
    import "../proxy/utils/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 onlyInitializing {
            __ReentrancyGuard_init_unchained();
        }
        function __ReentrancyGuard_init_unchained() internal onlyInitializing {
            _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 making 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;
        }
        /**
         * @dev This empty reserved space is put in place to allow future versions to add new
         * variables without shifting down storage in the inheritance chain.
         * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
         */
        uint256[49] private __gap;
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.7.0) (security/Pausable.sol)
    pragma solidity ^0.8.0;
    import "../utils/ContextUpgradeable.sol";
    import "../proxy/utils/Initializable.sol";
    /**
     * @dev Contract module which allows children to implement an emergency stop
     * mechanism that can be triggered by an authorized account.
     *
     * This module is used through inheritance. It will make available the
     * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
     * the functions of your contract. Note that they will not be pausable by
     * simply including this module, only once the modifiers are put in place.
     */
    abstract contract PausableUpgradeable is Initializable, ContextUpgradeable {
        /**
         * @dev Emitted when the pause is triggered by `account`.
         */
        event Paused(address account);
        /**
         * @dev Emitted when the pause is lifted by `account`.
         */
        event Unpaused(address account);
        bool private _paused;
        /**
         * @dev Initializes the contract in unpaused state.
         */
        function __Pausable_init() internal onlyInitializing {
            __Pausable_init_unchained();
        }
        function __Pausable_init_unchained() internal onlyInitializing {
            _paused = false;
        }
        /**
         * @dev Modifier to make a function callable only when the contract is not paused.
         *
         * Requirements:
         *
         * - The contract must not be paused.
         */
        modifier whenNotPaused() {
            _requireNotPaused();
            _;
        }
        /**
         * @dev Modifier to make a function callable only when the contract is paused.
         *
         * Requirements:
         *
         * - The contract must be paused.
         */
        modifier whenPaused() {
            _requirePaused();
            _;
        }
        /**
         * @dev Returns true if the contract is paused, and false otherwise.
         */
        function paused() public view virtual returns (bool) {
            return _paused;
        }
        /**
         * @dev Throws if the contract is paused.
         */
        function _requireNotPaused() internal view virtual {
            require(!paused(), "Pausable: paused");
        }
        /**
         * @dev Throws if the contract is not paused.
         */
        function _requirePaused() internal view virtual {
            require(paused(), "Pausable: not paused");
        }
        /**
         * @dev Triggers stopped state.
         *
         * Requirements:
         *
         * - The contract must not be paused.
         */
        function _pause() internal virtual whenNotPaused {
            _paused = true;
            emit Paused(_msgSender());
        }
        /**
         * @dev Returns to normal state.
         *
         * Requirements:
         *
         * - The contract must be paused.
         */
        function _unpause() internal virtual whenPaused {
            _paused = false;
            emit Unpaused(_msgSender());
        }
        /**
         * @dev This empty reserved space is put in place to allow future versions to add new
         * variables without shifting down storage in the inheritance chain.
         * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
         */
        uint256[49] private __gap;
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.7.0) (proxy/utils/Initializable.sol)
    pragma solidity ^0.8.2;
    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 proxied contracts do not make use of 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.
     *
     * The initialization functions use a version number. Once a version number is used, it is consumed and cannot be
     * reused. This mechanism prevents re-execution of each "step" but allows the creation of new initialization steps in
     * case an upgrade adds a module that needs to be initialized.
     *
     * For example:
     *
     * [.hljs-theme-light.nopadding]
     * ```
     * contract MyToken is ERC20Upgradeable {
     *     function initialize() initializer public {
     *         __ERC20_init("MyToken", "MTK");
     *     }
     * }
     * contract MyTokenV2 is MyToken, ERC20PermitUpgradeable {
     *     function initializeV2() reinitializer(2) public {
     *         __ERC20Permit_init("MyToken");
     *     }
     * }
     * ```
     *
     * 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 {ERC1967Proxy-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.
     *
     * [CAUTION]
     * ====
     * Avoid leaving a contract uninitialized.
     *
     * An uninitialized contract can be taken over by an attacker. This applies to both a proxy and its implementation
     * contract, which may impact the proxy. To prevent the implementation contract from being used, you should invoke
     * the {_disableInitializers} function in the constructor to automatically lock it when it is deployed:
     *
     * [.hljs-theme-light.nopadding]
     * ```
     * /// @custom:oz-upgrades-unsafe-allow constructor
     * constructor() {
     *     _disableInitializers();
     * }
     * ```
     * ====
     */
    abstract contract Initializable {
        /**
         * @dev Indicates that the contract has been initialized.
         * @custom:oz-retyped-from bool
         */
        uint8 private _initialized;
        /**
         * @dev Indicates that the contract is in the process of being initialized.
         */
        bool private _initializing;
        /**
         * @dev Triggered when the contract has been initialized or reinitialized.
         */
        event Initialized(uint8 version);
        /**
         * @dev A modifier that defines a protected initializer function that can be invoked at most once. In its scope,
         * `onlyInitializing` functions can be used to initialize parent contracts. Equivalent to `reinitializer(1)`.
         */
        modifier initializer() {
            bool isTopLevelCall = !_initializing;
            require(
                (isTopLevelCall && _initialized < 1) || (!AddressUpgradeable.isContract(address(this)) && _initialized == 1),
                "Initializable: contract is already initialized"
            );
            _initialized = 1;
            if (isTopLevelCall) {
                _initializing = true;
            }
            _;
            if (isTopLevelCall) {
                _initializing = false;
                emit Initialized(1);
            }
        }
        /**
         * @dev A modifier that defines a protected reinitializer function that can be invoked at most once, and only if the
         * contract hasn't been initialized to a greater version before. In its scope, `onlyInitializing` functions can be
         * used to initialize parent contracts.
         *
         * `initializer` is equivalent to `reinitializer(1)`, so a reinitializer may be used after the original
         * initialization step. This is essential to configure modules that are added through upgrades and that require
         * initialization.
         *
         * Note that versions can jump in increments greater than 1; this implies that if multiple reinitializers coexist in
         * a contract, executing them in the right order is up to the developer or operator.
         */
        modifier reinitializer(uint8 version) {
            require(!_initializing && _initialized < version, "Initializable: contract is already initialized");
            _initialized = version;
            _initializing = true;
            _;
            _initializing = false;
            emit Initialized(version);
        }
        /**
         * @dev Modifier to protect an initialization function so that it can only be invoked by functions with the
         * {initializer} and {reinitializer} modifiers, directly or indirectly.
         */
        modifier onlyInitializing() {
            require(_initializing, "Initializable: contract is not initializing");
            _;
        }
        /**
         * @dev Locks the contract, preventing any future reinitialization. This cannot be part of an initializer call.
         * Calling this in the constructor of a contract will prevent that contract from being initialized or reinitialized
         * to any version. It is recommended to use this to lock implementation contracts that are designed to be called
         * through proxies.
         */
        function _disableInitializers() internal virtual {
            require(!_initializing, "Initializable: contract is initializing");
            if (_initialized < type(uint8).max) {
                _initialized = type(uint8).max;
                emit Initialized(type(uint8).max);
            }
        }
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.6.0) (interfaces/IERC2981.sol)
    pragma solidity ^0.8.0;
    import "../utils/introspection/IERC165Upgradeable.sol";
    /**
     * @dev Interface for the NFT Royalty Standard.
     *
     * A standardized way to retrieve royalty payment information for non-fungible tokens (NFTs) to enable universal
     * support for royalty payments across all NFT marketplaces and ecosystem participants.
     *
     * _Available since v4.5._
     */
    interface IERC2981Upgradeable is IERC165Upgradeable {
        /**
         * @dev Returns how much royalty is owed and to whom, based on a sale price that may be denominated in any unit of
         * exchange. The royalty amount is denominated and should be paid in that same unit of exchange.
         */
        function royaltyInfo(uint256 tokenId, uint256 salePrice)
            external
            view
            returns (address receiver, uint256 royaltyAmount);
    }
    // SPDX-License-Identifier: MIT
    // OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)
    pragma solidity ^0.8.0;
    import "../utils/ContextUpgradeable.sol";
    import "../proxy/utils/Initializable.sol";
    /**
     * @dev Contract module which provides a basic access control mechanism, where
     * there is an account (an owner) that can be granted exclusive access to
     * specific functions.
     *
     * By default, the owner account will be the one that deploys the contract. This
     * can later be changed with {transferOwnership}.
     *
     * This module is used through inheritance. It will make available the modifier
     * `onlyOwner`, which can be applied to your functions to restrict their use to
     * the owner.
     */
    abstract contract OwnableUpgradeable is Initializable, ContextUpgradeable {
        address private _owner;
        event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
        /**
         * @dev Initializes the contract setting the deployer as the initial owner.
         */
        function __Ownable_init() internal onlyInitializing {
            __Ownable_init_unchained();
        }
        function __Ownable_init_unchained() internal onlyInitializing {
            _transferOwnership(_msgSender());
        }
        /**
         * @dev Throws if called by any account other than the owner.
         */
        modifier onlyOwner() {
            _checkOwner();
            _;
        }
        /**
         * @dev Returns the address of the current owner.
         */
        function owner() public view virtual returns (address) {
            return _owner;
        }
        /**
         * @dev Throws if the sender is not the owner.
         */
        function _checkOwner() internal view virtual {
            require(owner() == _msgSender(), "Ownable: caller is not the owner");
        }
        /**
         * @dev Leaves the contract without owner. It will not be possible to call
         * `onlyOwner` functions anymore. Can only be called by the current owner.
         *
         * NOTE: Renouncing ownership will leave the contract without an owner,
         * thereby removing any functionality that is only available to the owner.
         */
        function renounceOwnership() public virtual onlyOwner {
            _transferOwnership(address(0));
        }
        /**
         * @dev Transfers ownership of the contract to a new account (`newOwner`).
         * Can only be called by the current owner.
         */
        function transferOwnership(address newOwner) public virtual onlyOwner {
            require(newOwner != address(0), "Ownable: new owner is the zero address");
            _transferOwnership(newOwner);
        }
        /**
         * @dev Transfers ownership of the contract to a new account (`newOwner`).
         * Internal function without access restriction.
         */
        function _transferOwnership(address newOwner) internal virtual {
            address oldOwner = _owner;
            _owner = newOwner;
            emit OwnershipTransferred(oldOwner, newOwner);
        }
        /**
         * @dev This empty reserved space is put in place to allow future versions to add new
         * variables without shifting down storage in the inheritance chain.
         * See https://docs.openzeppelin.com/contracts/4.x/upgradeable#storage_gaps
         */
        uint256[49] private __gap;
    }