ETH Price: $1,979.75 (+6.13%)

Transaction Decoder

Block:
18364206 at Oct-16-2023 04:43:23 PM +UTC
Transaction Fee:
0.004778960660012 ETH $9.46
Gas Used:
215,600 Gas / 22.16586577 Gwei

Emitted Events:

257 0x1904780aeab48c05a846875eefa3c8b234a17b8d.0x4a504a94899432a9846e1aa406dceb1bcfd538bb839071d49d1e5e23f5be30ef( 0x4a504a94899432a9846e1aa406dceb1bcfd538bb839071d49d1e5e23f5be30ef, 0x000000000000000000000000f79244be8f46e4687a7150a76bfd821e775f26bb, 0x0000000000000000000000000000000000000000000000000000000000000000 )
258 0x93bf5828f7afff6139e704ba58ff87128e26c1e6.0x4a504a94899432a9846e1aa406dceb1bcfd538bb839071d49d1e5e23f5be30ef( 0x4a504a94899432a9846e1aa406dceb1bcfd538bb839071d49d1e5e23f5be30ef, 0x0000000000000000000000001904780aeab48c05a846875eefa3c8b234a17b8d, 0x0000000000000000000000000000000000000000000000000000000000000007 )
259 MintableToken.Transfer( from=0x93bf5828f7afff6139e704ba58ff87128e26c1e6, to=0x9280b7512CC02320d1a7C47d719Ce5757a65Aa4a, value=1819197827209202293915 )
260 0x93bf5828f7afff6139e704ba58ff87128e26c1e6.0xeb9df064f68e905565a2656b40e16dd2df0c9c21d72fda0d3a97de56f826f3d8( 0xeb9df064f68e905565a2656b40e16dd2df0c9c21d72fda0d3a97de56f826f3d8, 0x0000000000000000000000009280b7512cc02320d1a7c47d719ce5757a65aa4a, 0000000000000000000000000000000000000000000000629e710152d6f4dc9b )
261 0x1904780aeab48c05a846875eefa3c8b234a17b8d.0x33e13ecb54c3076d8e8bb8c2881800a4d972b792045ffae98fdf46df365fed75( 0x33e13ecb54c3076d8e8bb8c2881800a4d972b792045ffae98fdf46df365fed75, 0x0000000000000000000000000000000000000000000000000000000000000000 )

Account State Difference:

  Address   Before After State Difference Code
(MEV Builder: 0x0Aa...667)
14.383049848201805074 Eth14.383071408201805074 Eth0.00002156
0x1904780a...234A17b8d
0x29239242...05A4A4455
0x93BF5828...28E26C1e6
0xF79244be...e775f26bB
0.09844894467900088 Eth
Nonce: 79
0.09366998401898888 Eth
Nonce: 80
0.004778960660012

Execution Trace

0x1904780aeab48c05a846875eefa3c8b234a17b8d.c01a8c84( )
  • MultiSigWallet.confirmTransaction( transactionId=0 )
    • 0x93bf5828f7afff6139e704ba58ff87128e26c1e6.c01a8c84( )
      • 0x17034d060ca90b9e6d722cb798c1b605cd9036d6.c01a8c84( )
        • MintableToken.balanceOf( _owner=0x93BF5828f7AFff6139E704ba58fF87128E26C1e6 ) => ( balance=18493000564957767133965 )
        • MintableToken.transfer( _to=0x9280b7512CC02320d1a7C47d719Ce5757a65Aa4a, _value=1819197827209202293915 ) => ( True )
          File 1 of 2: MintableToken
          pragma solidity ^0.5.10;
          
          /**
           * @title Ownable
           * @dev The Ownable contract has an owner address, and provides basic authorization control
           * functions, this simplifies the implementation of "user permissions".
           */
          contract Ownable {
              address public owner;
          
          
              event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
          
          
              /**
               * @dev The Ownable constructor sets the original `owner` of the contract to the sender
               * account.
               */
              constructor() public {
                  owner = msg.sender;
              }
          
          
              /**
               * @dev Throws if called by any account other than the owner.
               */
              modifier onlyOwner() {
                  require(msg.sender == owner, "Not authorized operation");
                  _;
              }
          
          
              /**
               * @dev Allows the current owner to transfer control of the contract to a newOwner.
               * @param newOwner The address to transfer ownership to.
               */
              function transferOwnership(address newOwner) public onlyOwner {
                  require(newOwner != address(0), "Address shouldn't be zero");
                  emit OwnershipTransferred(owner, newOwner);
                  owner = newOwner;
              }
          
          }
          
          /**
           * @dev Wrappers over Solidity's arithmetic operations with added overflow
           * checks.
           *
           * Arithmetic operations in Solidity wrap on overflow. This can easily result
           * in bugs, because programmers usually assume that an overflow raises an
           * error, which is the standard behavior in high level programming languages.
           * `SafeMath` restores this intuition by reverting the transaction when an
           * operation overflows.
           *
           * Using this library instead of the unchecked operations eliminates an entire
           * class of bugs, so it's recommended to use it always.
           */
          library SafeMath {
              /**
               * @dev Returns the addition of two unsigned integers, reverting on
               * overflow.
               *
               * Counterpart to Solidity's `+` operator.
               *
               * Requirements:
               * - Addition cannot overflow.
               */
              function add(uint256 a, uint256 b) internal pure returns (uint256) {
                  uint256 c = a + b;
                  require(c >= a, "SafeMath: addition overflow");
          
                  return c;
              }
          
              /**
               * @dev Returns the subtraction of two unsigned integers, reverting on
               * overflow (when the result is negative).
               *
               * Counterpart to Solidity's `-` operator.
               *
               * Requirements:
               * - Subtraction cannot overflow.
               */
              function sub(uint256 a, uint256 b) internal pure returns (uint256) {
                  require(b <= a, "SafeMath: subtraction overflow");
                  uint256 c = a - b;
          
                  return c;
              }
          
              /**
               * @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) {
                  // 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-solidity/pull/522
                  if (a == 0) {
                      return 0;
                  }
          
                  uint256 c = a * b;
                  require(c / a == b, "SafeMath: multiplication overflow");
          
                  return c;
              }
          
              /**
               * @dev Returns the integer division of two unsigned integers. Reverts on
               * division by zero. The result is rounded towards zero.
               *
               * Counterpart to Solidity's `/` operator. Note: this function uses a
               * `revert` opcode (which leaves remaining gas untouched) while Solidity
               * uses an invalid opcode to revert (consuming all remaining gas).
               *
               * Requirements:
               * - The divisor cannot be zero.
               */
              function div(uint256 a, uint256 b) internal pure returns (uint256) {
                  // Solidity only automatically asserts when dividing by 0
                  require(b > 0, "SafeMath: division by zero");
                  uint256 c = a / b;
                  // assert(a == b * c + a % b); // There is no case in which this doesn't hold
          
                  return c;
              }
          
              /**
               * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
               * Reverts when dividing by zero.
               *
               * Counterpart to Solidity's `%` operator. This function uses a `revert`
               * opcode (which leaves remaining gas untouched) while Solidity uses an
               * invalid opcode to revert (consuming all remaining gas).
               *
               * Requirements:
               * - The divisor cannot be zero.
               */
              function mod(uint256 a, uint256 b) internal pure returns (uint256) {
                  require(b != 0, "SafeMath: modulo by zero");
                  return a % b;
              }
          }
          
          /**
           * @title ERC20 interface
           * @dev see https://github.com/ethereum/EIPs/issues/20
           */
          contract ERC20 {
            uint256 public totalSupply;
            function balanceOf(address who) public view returns (uint256);
            function transfer(address to, uint256 value) public returns (bool);
            function allowance(address owner, address spender) public view returns (uint256);
            function transferFrom(address from, address to, uint256 value) public returns (bool);
            function approve(address spender, uint256 value) public returns (bool);
            event Approval(address indexed owner, address indexed spender, uint256 value);
            event Transfer(address indexed from, address indexed to, uint256 value);
          
          
          }
          
          /**
           * @dev Collection of functions related to the address type,
           */
          library Address {
              /**
               * @dev Returns true if `account` is a contract.
               *
               * This test is non-exhaustive, and there may be false-negatives: during the
               * execution of a contract's constructor, its address will be reported as
               * not containing a contract.
               *
               * > It is unsafe to assume that an address for which this function returns
               * false is an externally-owned account (EOA) and not a contract.
               */
              function isContract(address account) internal view returns (bool) {
                  // This method relies in extcodesize, which returns 0 for contracts in
                  // construction, since the code is only stored at the end of the
                  // constructor execution.
          
                  uint256 size;
                  // solhint-disable-next-line no-inline-assembly
                  assembly { size := extcodesize(account) }
                  return size > 0;
              }
          }
          
          /**
           * @title Tozex ERC20 Mintable token
           * @dev Issue: contact support@tozex.io
           * @author Tozex.io
           */
          contract MintableToken is ERC20, Ownable {
            using Address for address;
            using SafeMath for uint256;
          
            string public name;
            string public symbol;
            uint8 public decimals;
            uint256 public totalSupply;
            address public tokenOwner;
            address private crowdsale;
          
            mapping(address => uint256) balances;
            mapping(address => mapping(address => uint256)) internal allowed;
          
            event SetCrowdsale(address indexed _crowdsale);
            event Mint(address indexed to, uint256 amount);
            event MintFinished();
            event UnlockToken();
            event LockToken();
            event Burn();
          
            bool public mintingFinished = false;
            bool public locked = false;
          
          
            modifier canMint() {
              require(!mintingFinished);
              _;
            }
          
            modifier canTransfer() {
              require(!locked || msg.sender == owner);
              _;
            }
          
            modifier onlyCrowdsale() {
              require(msg.sender == crowdsale);
              _;
            }
          
            modifier onlyAuthorized() {
              require(msg.sender == owner || msg.sender == crowdsale);
              _;
            }
          
            constructor(string memory _name, string memory _symbol, uint8 _decimals) public {
              name = _name;
              symbol = _symbol;
              decimals = _decimals;
              totalSupply = 0;
              balances[msg.sender] = totalSupply;
              emit Transfer(address(0), msg.sender, totalSupply);
            }
          
            /**
             * @dev Function to mint tokens
             * @param _amount The amount of tokens to mint.
             * @return A boolean that indicates if the operation was successful.
             */
            function mint(address _to, uint256 _amount) public onlyAuthorized canMint returns (bool) {
              totalSupply = totalSupply.add(_amount);
              balances[_to] = balances[_to].add(_amount);
              emit Mint(_to, _amount);
              emit Transfer(address(0), _to, _amount);
              return true;
            }
          
            /**
             * @dev Function to stop minting new tokens.
             * @return True if the operation was successful.
             */
            function finishMinting() onlyOwner public canMint returns (bool) {
              mintingFinished = true;
              emit MintFinished();
              return true;
            }
          
            function burn(uint256 _value) public onlyAuthorized returns (bool) {
              totalSupply = totalSupply.sub(_value);
              balances[address(this)] = balances[address(this)].sub(_value);
              emit Burn();
              emit Transfer(address(this), address(0), _value);
              return true;
            }
            /**
            * @dev transfer token for a specified address
            * @param _to The address to transfer to.
            * @param _value The amount to be transferred.
            */
          
            function transfer(address _to, uint256 _value) public canTransfer returns (bool) {
              require(_to != address(0));
              require(_value <= balances[msg.sender]);
          
              // SafeMath.sub will throw if there is not enough balance.
              balances[msg.sender] = balances[msg.sender].sub(_value);
              balances[_to] = balances[_to].add(_value);
              emit Transfer(msg.sender, _to, _value);
              return true;
            }
          
            function transferFromContract(address _to, uint256 _value) public onlyOwner returns (bool) {
              require(_to != address(0));
              require(_value <= balances[address(this)]);
              balances[address(this)] = balances[address(this)].sub(_value);
              balances[_to] = balances[_to].add(_value);
              emit Transfer(address(this), _to, _value);
              return true;
            }
          
            /**
            * @dev Gets the balance of the specified address.
            * @param _owner The address to query the the balance of.
            * @return An uint256 representing the amount owned by the passed address.
            */
            function balanceOf(address _owner) public view returns (uint256 balance) {
              return balances[_owner];
            }
          
            /**
             * @dev Transfer tokens from one address to another
             * @param _from address The address which you want to send tokens from
             * @param _to address The address which you want to transfer to
             * @param _value uint256 the amount of tokens to be transferred
             */
            function transferFrom(address _from, address _to, uint256 _value) public canTransfer returns (bool) {
              require(_to != address(0));
              require(_value <= balances[_from]);
              require(_value <= allowed[_from][msg.sender]);
          
              balances[_from] = balances[_from].sub(_value);
              balances[_to] = balances[_to].add(_value);
              allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
              emit Transfer(_from, _to, _value);
              return true;
            }
          
            /**
             * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
             *
             * Beware that changing an allowance with this method brings the risk that someone may use both the old
             * and the new allowance by unfortunate transaction ordering. One possible solution to mitigate this
             * race condition is to first reduce the spender's allowance to 0 and set the desired value afterwards:
             * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
             * @param _spender The address which will spend the funds.
             * @param _value The amount of tokens to be spent.
             */
            function approve(address _spender, uint256 _value) public returns (bool) {
              allowed[msg.sender][_spender] = _value;
              emit Approval(msg.sender, _spender, _value);
              return true;
            }
          
            /**
             * @dev Function to check the amount of tokens that an owner allowed to a spender.
             * @param _owner address The address which owns the funds.
             * @param _spender address The address which will spend the funds.
             * @return A uint256 specifying the amount of tokens still available for the spender.
             */
            function allowance(address _owner, address _spender) public view returns (uint256) {
              return allowed[_owner][_spender];
            }
          
            /**
             * @dev Increase the amount of tokens that an owner allowed to a spender.
             *
             * approve should be called when allowed[_spender] == 0. To increment
             * allowed value is better to use this function to avoid 2 calls (and wait until
             * the first transaction is mined)
             * From MonolithDAO Token.sol
             * @param _spender The address which will spend the funds.
             * @param _addedValue The amount of tokens to increase the allowance by.
             */
            function increaseApproval(address _spender, uint _addedValue) public returns (bool) {
              allowed[msg.sender][_spender] = allowed[msg.sender][_spender].add(_addedValue);
              emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
              return true;
            }
          
            /**
             * @dev Decrease the amount of tokens that an owner allowed to a spender.
             *
             * approve should be called when allowed[_spender] == 0. To decrement
             * allowed value is better to use this function to avoid 2 calls (and wait until
             * the first transaction is mined)
             * From MonolithDAO Token.sol
             * @param _spender The address which will spend the funds.
             * @param _subtractedValue The amount of tokens to decrease the allowance by.
             */
            function decreaseApproval(address _spender, uint _subtractedValue) public returns (bool) {
              uint oldValue = allowed[msg.sender][_spender];
          
              if (_subtractedValue > oldValue) {
                allowed[msg.sender][_spender] = 0;
              } else {
                allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue);
              }
          
              emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
              return true;
            }
          
            function unlockToken() public onlyCrowdsale returns (bool) {
              locked = false;
              emit UnlockToken();
              return true;
            }
          
            function lockToken() public onlyCrowdsale returns (bool) {
              locked = true;
              emit LockToken();
              return true;
            }
          
            function setCrowdsale(address _crowdsale) public onlyOwner returns (bool) {
              require(_crowdsale.isContract());
              crowdsale = _crowdsale;
          
              emit SetCrowdsale(_crowdsale);
              return true;
            }
          }

          File 2 of 2: MultiSigWallet
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts (last updated v4.9.0) (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. Can only be called by the current owner.
               *
               * NOTE: Renouncing ownership will leave the contract without an owner,
               * thereby disabling 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;
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts (last updated v4.9.0) (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]
           * ```solidity
           * 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.
               *
               * Similar to `reinitializer(1)`, except that functions marked with `initializer` can be nested in the context of a
               * constructor.
               *
               * Emits an {Initialized} event.
               */
              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.
               *
               * 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.
               *
               * When `version` is 1, this modifier is similar to `initializer`, except that functions marked with `reinitializer`
               * cannot be nested. If one is invoked in the context of another, execution will revert.
               *
               * 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.
               *
               * WARNING: setting the version to 255 will prevent any future reinitialization.
               *
               * Emits an {Initialized} event.
               */
              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.
               *
               * Emits an {Initialized} event the first time it is successfully executed.
               */
              function _disableInitializers() internal virtual {
                  require(!_initializing, "Initializable: contract is initializing");
                  if (_initialized != type(uint8).max) {
                      _initialized = type(uint8).max;
                      emit Initialized(type(uint8).max);
                  }
              }
              /**
               * @dev Returns the highest version that has been initialized. See {reinitializer}.
               */
              function _getInitializedVersion() internal view returns (uint8) {
                  return _initialized;
              }
              /**
               * @dev Returns `true` if the contract is currently initializing. See {onlyInitializing}.
               */
              function _isInitializing() internal view returns (bool) {
                  return _initializing;
              }
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts (last updated v4.5.0) (token/ERC1155/IERC1155Receiver.sol)
          pragma solidity ^0.8.0;
          import "../../utils/introspection/IERC165Upgradeable.sol";
          /**
           * @dev _Available since v3.1._
           */
          interface IERC1155ReceiverUpgradeable is IERC165Upgradeable {
              /**
               * @dev Handles the receipt of a single ERC1155 token type. This function is
               * called at the end of a `safeTransferFrom` after the balance has been updated.
               *
               * NOTE: To accept the transfer, this must return
               * `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))`
               * (i.e. 0xf23a6e61, or its own function selector).
               *
               * @param operator The address which initiated the transfer (i.e. msg.sender)
               * @param from The address which previously owned the token
               * @param id The ID of the token being transferred
               * @param value The amount of tokens being transferred
               * @param data Additional data with no specified format
               * @return `bytes4(keccak256("onERC1155Received(address,address,uint256,uint256,bytes)"))` if transfer is allowed
               */
              function onERC1155Received(
                  address operator,
                  address from,
                  uint256 id,
                  uint256 value,
                  bytes calldata data
              ) external returns (bytes4);
              /**
               * @dev Handles the receipt of a multiple ERC1155 token types. This function
               * is called at the end of a `safeBatchTransferFrom` after the balances have
               * been updated.
               *
               * NOTE: To accept the transfer(s), this must return
               * `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))`
               * (i.e. 0xbc197c81, or its own function selector).
               *
               * @param operator The address which initiated the batch transfer (i.e. msg.sender)
               * @param from The address which previously owned the token
               * @param ids An array containing ids of each token being transferred (order and length must match values array)
               * @param values An array containing amounts of each token being transferred (order and length must match ids array)
               * @param data Additional data with no specified format
               * @return `bytes4(keccak256("onERC1155BatchReceived(address,address,uint256[],uint256[],bytes)"))` if transfer is allowed
               */
              function onERC1155BatchReceived(
                  address operator,
                  address from,
                  uint256[] calldata ids,
                  uint256[] calldata values,
                  bytes calldata data
              ) external returns (bytes4);
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts (last updated v4.9.0) (token/ERC1155/IERC1155.sol)
          pragma solidity ^0.8.0;
          import "../../utils/introspection/IERC165Upgradeable.sol";
          /**
           * @dev Required interface of an ERC1155 compliant contract, as defined in the
           * https://eips.ethereum.org/EIPS/eip-1155[EIP].
           *
           * _Available since v3.1._
           */
          interface IERC1155Upgradeable is IERC165Upgradeable {
              /**
               * @dev Emitted when `value` tokens of token type `id` are transferred from `from` to `to` by `operator`.
               */
              event TransferSingle(address indexed operator, address indexed from, address indexed to, uint256 id, uint256 value);
              /**
               * @dev Equivalent to multiple {TransferSingle} events, where `operator`, `from` and `to` are the same for all
               * transfers.
               */
              event TransferBatch(
                  address indexed operator,
                  address indexed from,
                  address indexed to,
                  uint256[] ids,
                  uint256[] values
              );
              /**
               * @dev Emitted when `account` grants or revokes permission to `operator` to transfer their tokens, according to
               * `approved`.
               */
              event ApprovalForAll(address indexed account, address indexed operator, bool approved);
              /**
               * @dev Emitted when the URI for token type `id` changes to `value`, if it is a non-programmatic URI.
               *
               * If an {URI} event was emitted for `id`, the standard
               * https://eips.ethereum.org/EIPS/eip-1155#metadata-extensions[guarantees] that `value` will equal the value
               * returned by {IERC1155MetadataURI-uri}.
               */
              event URI(string value, uint256 indexed id);
              /**
               * @dev Returns the amount of tokens of token type `id` owned by `account`.
               *
               * Requirements:
               *
               * - `account` cannot be the zero address.
               */
              function balanceOf(address account, uint256 id) external view returns (uint256);
              /**
               * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {balanceOf}.
               *
               * Requirements:
               *
               * - `accounts` and `ids` must have the same length.
               */
              function balanceOfBatch(
                  address[] calldata accounts,
                  uint256[] calldata ids
              ) external view returns (uint256[] memory);
              /**
               * @dev Grants or revokes permission to `operator` to transfer the caller's tokens, according to `approved`,
               *
               * Emits an {ApprovalForAll} event.
               *
               * Requirements:
               *
               * - `operator` cannot be the caller.
               */
              function setApprovalForAll(address operator, bool approved) external;
              /**
               * @dev Returns true if `operator` is approved to transfer ``account``'s tokens.
               *
               * See {setApprovalForAll}.
               */
              function isApprovedForAll(address account, address operator) external view returns (bool);
              /**
               * @dev Transfers `amount` tokens of token type `id` from `from` to `to`.
               *
               * Emits a {TransferSingle} event.
               *
               * Requirements:
               *
               * - `to` cannot be the zero address.
               * - If the caller is not `from`, it must have been approved to spend ``from``'s tokens via {setApprovalForAll}.
               * - `from` must have a balance of tokens of type `id` of at least `amount`.
               * - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155Received} and return the
               * acceptance magic value.
               */
              function safeTransferFrom(address from, address to, uint256 id, uint256 amount, bytes calldata data) external;
              /**
               * @dev xref:ROOT:erc1155.adoc#batch-operations[Batched] version of {safeTransferFrom}.
               *
               * Emits a {TransferBatch} event.
               *
               * Requirements:
               *
               * - `ids` and `amounts` must have the same length.
               * - If `to` refers to a smart contract, it must implement {IERC1155Receiver-onERC1155BatchReceived} and return the
               * acceptance magic value.
               */
              function safeBatchTransferFrom(
                  address from,
                  address to,
                  uint256[] calldata ids,
                  uint256[] calldata amounts,
                  bytes calldata data
              ) external;
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts v4.4.1 (token/ERC1155/utils/ERC1155Receiver.sol)
          pragma solidity ^0.8.0;
          import "../IERC1155ReceiverUpgradeable.sol";
          import "../../../utils/introspection/ERC165Upgradeable.sol";
          import "../../../proxy/utils/Initializable.sol";
          /**
           * @dev _Available since v3.1._
           */
          abstract contract ERC1155ReceiverUpgradeable is Initializable, ERC165Upgradeable, IERC1155ReceiverUpgradeable {
              function __ERC1155Receiver_init() internal onlyInitializing {
              }
              function __ERC1155Receiver_init_unchained() internal onlyInitializing {
              }
              /**
               * @dev See {IERC165-supportsInterface}.
               */
              function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165Upgradeable, IERC165Upgradeable) returns (bool) {
                  return interfaceId == type(IERC1155ReceiverUpgradeable).interfaceId || super.supportsInterface(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 v4.9.0) (token/ERC20/extensions/IERC20Permit.sol)
          pragma solidity ^0.8.0;
          /**
           * @dev Interface of the ERC20 Permit extension allowing approvals to be made via signatures, as defined in
           * https://eips.ethereum.org/EIPS/eip-2612[EIP-2612].
           *
           * Adds the {permit} method, which can be used to change an account's ERC20 allowance (see {IERC20-allowance}) by
           * presenting a message signed by the account. By not relying on {IERC20-approve}, the token holder account doesn't
           * need to send a transaction, and thus is not required to hold Ether at all.
           */
          interface IERC20PermitUpgradeable {
              /**
               * @dev Sets `value` as the allowance of `spender` over ``owner``'s tokens,
               * given ``owner``'s signed approval.
               *
               * IMPORTANT: The same issues {IERC20-approve} has related to transaction
               * ordering also apply here.
               *
               * Emits an {Approval} event.
               *
               * Requirements:
               *
               * - `spender` cannot be the zero address.
               * - `deadline` must be a timestamp in the future.
               * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
               * over the EIP712-formatted function arguments.
               * - the signature must use ``owner``'s current nonce (see {nonces}).
               *
               * For more information on the signature format, see the
               * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
               * section].
               */
              function permit(
                  address owner,
                  address spender,
                  uint256 value,
                  uint256 deadline,
                  uint8 v,
                  bytes32 r,
                  bytes32 s
              ) external;
              /**
               * @dev Returns the current nonce for `owner`. This value must be
               * included whenever a signature is generated for {permit}.
               *
               * Every successful call to {permit} increases ``owner``'s nonce by one. This
               * prevents a signature from being used multiple times.
               */
              function nonces(address owner) external view returns (uint256);
              /**
               * @dev Returns the domain separator used in the encoding of the signature for {permit}, as defined by {EIP712}.
               */
              // solhint-disable-next-line func-name-mixedcase
              function DOMAIN_SEPARATOR() external view returns (bytes32);
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)
          pragma solidity ^0.8.0;
          /**
           * @dev Interface of the ERC20 standard as defined in the EIP.
           */
          interface IERC20Upgradeable {
              /**
               * @dev Emitted when `value` tokens are moved from one account (`from`) to
               * another (`to`).
               *
               * Note that `value` may be zero.
               */
              event Transfer(address indexed from, address indexed to, uint256 value);
              /**
               * @dev Emitted when the allowance of a `spender` for an `owner` is set by
               * a call to {approve}. `value` is the new allowance.
               */
              event Approval(address indexed owner, address indexed spender, uint256 value);
              /**
               * @dev Returns the amount of tokens in existence.
               */
              function totalSupply() external view returns (uint256);
              /**
               * @dev Returns the amount of tokens owned by `account`.
               */
              function balanceOf(address account) external view returns (uint256);
              /**
               * @dev Moves `amount` tokens from the caller's account to `to`.
               *
               * Returns a boolean value indicating whether the operation succeeded.
               *
               * Emits a {Transfer} event.
               */
              function transfer(address to, uint256 amount) external returns (bool);
              /**
               * @dev Returns the remaining number of tokens that `spender` will be
               * allowed to spend on behalf of `owner` through {transferFrom}. This is
               * zero by default.
               *
               * This value changes when {approve} or {transferFrom} are called.
               */
              function allowance(address owner, address spender) external view returns (uint256);
              /**
               * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
               *
               * Returns a boolean value indicating whether the operation succeeded.
               *
               * IMPORTANT: Beware that changing an allowance with this method brings the risk
               * that someone may use both the old and the new allowance by unfortunate
               * transaction ordering. One possible solution to mitigate this race
               * condition is to first reduce the spender's allowance to 0 and set the
               * desired value afterwards:
               * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
               *
               * Emits an {Approval} event.
               */
              function approve(address spender, uint256 amount) external returns (bool);
              /**
               * @dev Moves `amount` tokens from `from` to `to` using the
               * allowance mechanism. `amount` is then deducted from the caller's
               * allowance.
               *
               * Returns a boolean value indicating whether the operation succeeded.
               *
               * Emits a {Transfer} event.
               */
              function transferFrom(address from, address to, uint256 amount) external returns (bool);
          }
          // SPDX-License-Identifier: MIT
          // OpenZeppelin Contracts (last updated v4.9.3) (token/ERC20/utils/SafeERC20.sol)
          pragma solidity ^0.8.0;
          import "../IERC20Upgradeable.sol";
          import "../extensions/IERC20PermitUpgradeable.sol";
          import "../../../utils/AddressUpgradeable.sol";
          /**
           * @title SafeERC20
           * @dev Wrappers around ERC20 operations that throw on failure (when the token
           * contract returns false). Tokens that return no value (and instead revert or
           * throw on failure) are also supported, non-reverting calls are assumed to be
           * successful.
           * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
           * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
           */
          library SafeERC20Upgradeable {
              using AddressUpgradeable for address;
              /**
               * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
               * non-reverting calls are assumed to be successful.
               */
              function safeTransfer(IERC20Upgradeable token, address to, uint256 value) internal {
                  _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
              }
              /**
               * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
               * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
               */
              function safeTransferFrom(IERC20Upgradeable token, address from, address to, uint256 value) internal {
                  _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
              }
              /**
               * @dev Deprecated. This function has issues similar to the ones found in
               * {IERC20-approve}, and its usage is discouraged.
               *
               * Whenever possible, use {safeIncreaseAllowance} and
               * {safeDecreaseAllowance} instead.
               */
              function safeApprove(IERC20Upgradeable token, address spender, uint256 value) internal {
                  // safeApprove should only be called when setting an initial allowance,
                  // or when resetting it to zero. To increase and decrease it, use
                  // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
                  require(
                      (value == 0) || (token.allowance(address(this), spender) == 0),
                      "SafeERC20: approve from non-zero to non-zero allowance"
                  );
                  _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
              }
              /**
               * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
               * non-reverting calls are assumed to be successful.
               */
              function safeIncreaseAllowance(IERC20Upgradeable token, address spender, uint256 value) internal {
                  uint256 oldAllowance = token.allowance(address(this), spender);
                  _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance + value));
              }
              /**
               * @dev Decrease the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
               * non-reverting calls are assumed to be successful.
               */
              function safeDecreaseAllowance(IERC20Upgradeable token, address spender, uint256 value) internal {
                  unchecked {
                      uint256 oldAllowance = token.allowance(address(this), spender);
                      require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
                      _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, oldAllowance - value));
                  }
              }
              /**
               * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
               * non-reverting calls are assumed to be successful. Meant to be used with tokens that require the approval
               * to be set to zero before setting it to a non-zero value, such as USDT.
               */
              function forceApprove(IERC20Upgradeable token, address spender, uint256 value) internal {
                  bytes memory approvalCall = abi.encodeWithSelector(token.approve.selector, spender, value);
                  if (!_callOptionalReturnBool(token, approvalCall)) {
                      _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, 0));
                      _callOptionalReturn(token, approvalCall);
                  }
              }
              /**
               * @dev Use a ERC-2612 signature to set the `owner` approval toward `spender` on `token`.
               * Revert on invalid signature.
               */
              function safePermit(
                  IERC20PermitUpgradeable token,
                  address owner,
                  address spender,
                  uint256 value,
                  uint256 deadline,
                  uint8 v,
                  bytes32 r,
                  bytes32 s
              ) internal {
                  uint256 nonceBefore = token.nonces(owner);
                  token.permit(owner, spender, value, deadline, v, r, s);
                  uint256 nonceAfter = token.nonces(owner);
                  require(nonceAfter == nonceBefore + 1, "SafeERC20: permit did not succeed");
              }
              /**
               * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
               * on the return value: the return value is optional (but if data is returned, it must not be false).
               * @param token The token targeted by the call.
               * @param data The call data (encoded using abi.encode or one of its variants).
               */
              function _callOptionalReturn(IERC20Upgradeable token, bytes memory data) private {
                  // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
                  // we're implementing it ourselves. We use {Address-functionCall} to perform this call, which verifies that
                  // the target address contains contract code and also asserts for success in the low-level call.
                  bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
                  require(returndata.length == 0 || abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
              }
              /**
               * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
               * on the return value: the return value is optional (but if data is returned, it must not be false).
               * @param token The token targeted by the call.
               * @param data The call data (encoded using abi.encode or one of its variants).
               *
               * This is a variant of {_callOptionalReturn} that silents catches all reverts and returns a bool instead.
               */
              function _callOptionalReturnBool(IERC20Upgradeable token, bytes memory data) private returns (bool) {
                  // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
                  // we're implementing it ourselves. We cannot use {Address-functionCall} here since this should return false
                  // and not revert is the subcall reverts.
                  (bool success, bytes memory returndata) = address(token).call(data);
                  return
                      success && (returndata.length == 0 || abi.decode(returndata, (bool))) && AddressUpgradeable.isContract(address(token));
              }
          }
          // 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 v4.9.0) (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: Note that the caller is responsible to confirm that the recipient is capable of receiving ERC721
               * or else they may be permanently lost. Usage of {safeTransferFrom} prevents loss, though the caller must
               * understand this adds an external call which potentially creates a reentrancy vulnerability.
               *
               * 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 v4.9.0) (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
               *
               * Furthermore, `isContract` will also return true if the target contract within
               * the same transaction is already scheduled for destruction by `SELFDESTRUCT`,
               * which only has an effect at the end of a transaction.
               * ====
               *
               * [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://consensys.net/diligence/blog/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/v0.8.0/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 functionCallWithValue(target, data, 0, "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");
                  (bool success, bytes memory returndata) = target.call{value: value}(data);
                  return verifyCallResultFromTarget(target, 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) {
                  (bool success, bytes memory returndata) = target.staticcall(data);
                  return verifyCallResultFromTarget(target, 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) {
                  (bool success, bytes memory returndata) = target.delegatecall(data);
                  return verifyCallResultFromTarget(target, success, returndata, errorMessage);
              }
              /**
               * @dev Tool to verify that a low level call to smart-contract was successful, and revert (either by bubbling
               * the revert reason or using the provided one) in case of unsuccessful call or if target was not a contract.
               *
               * _Available since v4.8._
               */
              function verifyCallResultFromTarget(
                  address target,
                  bool success,
                  bytes memory returndata,
                  string memory errorMessage
              ) internal view returns (bytes memory) {
                  if (success) {
                      if (returndata.length == 0) {
                          // only check isContract if the call was successful and the return data is empty
                          // otherwise we already know that it was a contract
                          require(isContract(target), "Address: call to non-contract");
                      }
                      return returndata;
                  } else {
                      _revert(returndata, errorMessage);
                  }
              }
              /**
               * @dev Tool to verify that a low level call was successful, and revert if it wasn't, either by bubbling the
               * revert reason or 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 {
                      _revert(returndata, errorMessage);
                  }
              }
              function _revert(bytes memory returndata, string memory errorMessage) private pure {
                  // 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/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 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 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 (last updated v4.9.0) (utils/math/Math.sol)
          pragma solidity ^0.8.0;
          /**
           * @dev Standard math utilities missing in the Solidity language.
           */
          library MathUpgradeable {
              enum Rounding {
                  Down, // Toward negative infinity
                  Up, // Toward infinity
                  Zero // Toward zero
              }
              /**
               * @dev Returns the largest of two numbers.
               */
              function max(uint256 a, uint256 b) internal pure returns (uint256) {
                  return a > b ? a : b;
              }
              /**
               * @dev Returns the smallest of two numbers.
               */
              function min(uint256 a, uint256 b) internal pure returns (uint256) {
                  return a < b ? a : b;
              }
              /**
               * @dev Returns the average of two numbers. The result is rounded towards
               * zero.
               */
              function average(uint256 a, uint256 b) internal pure returns (uint256) {
                  // (a + b) / 2 can overflow.
                  return (a & b) + (a ^ b) / 2;
              }
              /**
               * @dev Returns the ceiling of the division of two numbers.
               *
               * This differs from standard division with `/` in that it rounds up instead
               * of rounding down.
               */
              function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
                  // (a + b - 1) / b can overflow on addition, so we distribute.
                  return a == 0 ? 0 : (a - 1) / b + 1;
              }
              /**
               * @notice Calculates floor(x * y / denominator) with full precision. Throws if result overflows a uint256 or denominator == 0
               * @dev Original credit to Remco Bloemen under MIT license (https://xn--2-umb.com/21/muldiv)
               * with further edits by Uniswap Labs also under MIT license.
               */
              function mulDiv(uint256 x, uint256 y, uint256 denominator) internal pure returns (uint256 result) {
                  unchecked {
                      // 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2^256 and mod 2^256 - 1, then use
                      // use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
                      // variables such that product = prod1 * 2^256 + prod0.
                      uint256 prod0; // Least significant 256 bits of the product
                      uint256 prod1; // Most significant 256 bits of the product
                      assembly {
                          let mm := mulmod(x, y, not(0))
                          prod0 := mul(x, y)
                          prod1 := sub(sub(mm, prod0), lt(mm, prod0))
                      }
                      // Handle non-overflow cases, 256 by 256 division.
                      if (prod1 == 0) {
                          // Solidity will revert if denominator == 0, unlike the div opcode on its own.
                          // The surrounding unchecked block does not change this fact.
                          // See https://docs.soliditylang.org/en/latest/control-structures.html#checked-or-unchecked-arithmetic.
                          return prod0 / denominator;
                      }
                      // Make sure the result is less than 2^256. Also prevents denominator == 0.
                      require(denominator > prod1, "Math: mulDiv overflow");
                      ///////////////////////////////////////////////
                      // 512 by 256 division.
                      ///////////////////////////////////////////////
                      // Make division exact by subtracting the remainder from [prod1 prod0].
                      uint256 remainder;
                      assembly {
                          // Compute remainder using mulmod.
                          remainder := mulmod(x, y, denominator)
                          // Subtract 256 bit number from 512 bit number.
                          prod1 := sub(prod1, gt(remainder, prod0))
                          prod0 := sub(prod0, remainder)
                      }
                      // Factor powers of two out of denominator and compute largest power of two divisor of denominator. Always >= 1.
                      // See https://cs.stackexchange.com/q/138556/92363.
                      // Does not overflow because the denominator cannot be zero at this stage in the function.
                      uint256 twos = denominator & (~denominator + 1);
                      assembly {
                          // Divide denominator by twos.
                          denominator := div(denominator, twos)
                          // Divide [prod1 prod0] by twos.
                          prod0 := div(prod0, twos)
                          // Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
                          twos := add(div(sub(0, twos), twos), 1)
                      }
                      // Shift in bits from prod1 into prod0.
                      prod0 |= prod1 * twos;
                      // Invert denominator mod 2^256. Now that denominator is an odd number, it has an inverse modulo 2^256 such
                      // that denominator * inv = 1 mod 2^256. Compute the inverse by starting with a seed that is correct for
                      // four bits. That is, denominator * inv = 1 mod 2^4.
                      uint256 inverse = (3 * denominator) ^ 2;
                      // Use the Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also works
                      // in modular arithmetic, doubling the correct bits in each step.
                      inverse *= 2 - denominator * inverse; // inverse mod 2^8
                      inverse *= 2 - denominator * inverse; // inverse mod 2^16
                      inverse *= 2 - denominator * inverse; // inverse mod 2^32
                      inverse *= 2 - denominator * inverse; // inverse mod 2^64
                      inverse *= 2 - denominator * inverse; // inverse mod 2^128
                      inverse *= 2 - denominator * inverse; // inverse mod 2^256
                      // Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
                      // This will give us the correct result modulo 2^256. Since the preconditions guarantee that the outcome is
                      // less than 2^256, this is the final result. We don't need to compute the high bits of the result and prod1
                      // is no longer required.
                      result = prod0 * inverse;
                      return result;
                  }
              }
              /**
               * @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
               */
              function mulDiv(uint256 x, uint256 y, uint256 denominator, Rounding rounding) internal pure returns (uint256) {
                  uint256 result = mulDiv(x, y, denominator);
                  if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
                      result += 1;
                  }
                  return result;
              }
              /**
               * @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded down.
               *
               * Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
               */
              function sqrt(uint256 a) internal pure returns (uint256) {
                  if (a == 0) {
                      return 0;
                  }
                  // For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
                  //
                  // We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
                  // `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
                  //
                  // This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
                  // → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
                  // → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
                  //
                  // Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
                  uint256 result = 1 << (log2(a) >> 1);
                  // At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
                  // since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
                  // every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
                  // into the expected uint128 result.
                  unchecked {
                      result = (result + a / result) >> 1;
                      result = (result + a / result) >> 1;
                      result = (result + a / result) >> 1;
                      result = (result + a / result) >> 1;
                      result = (result + a / result) >> 1;
                      result = (result + a / result) >> 1;
                      result = (result + a / result) >> 1;
                      return min(result, a / result);
                  }
              }
              /**
               * @notice Calculates sqrt(a), following the selected rounding direction.
               */
              function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
                  unchecked {
                      uint256 result = sqrt(a);
                      return result + (rounding == Rounding.Up && result * result < a ? 1 : 0);
                  }
              }
              /**
               * @dev Return the log in base 2, rounded down, of a positive value.
               * Returns 0 if given 0.
               */
              function log2(uint256 value) internal pure returns (uint256) {
                  uint256 result = 0;
                  unchecked {
                      if (value >> 128 > 0) {
                          value >>= 128;
                          result += 128;
                      }
                      if (value >> 64 > 0) {
                          value >>= 64;
                          result += 64;
                      }
                      if (value >> 32 > 0) {
                          value >>= 32;
                          result += 32;
                      }
                      if (value >> 16 > 0) {
                          value >>= 16;
                          result += 16;
                      }
                      if (value >> 8 > 0) {
                          value >>= 8;
                          result += 8;
                      }
                      if (value >> 4 > 0) {
                          value >>= 4;
                          result += 4;
                      }
                      if (value >> 2 > 0) {
                          value >>= 2;
                          result += 2;
                      }
                      if (value >> 1 > 0) {
                          result += 1;
                      }
                  }
                  return result;
              }
              /**
               * @dev Return the log in base 2, following the selected rounding direction, of a positive value.
               * Returns 0 if given 0.
               */
              function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
                  unchecked {
                      uint256 result = log2(value);
                      return result + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
                  }
              }
              /**
               * @dev Return the log in base 10, rounded down, of a positive value.
               * Returns 0 if given 0.
               */
              function log10(uint256 value) internal pure returns (uint256) {
                  uint256 result = 0;
                  unchecked {
                      if (value >= 10 ** 64) {
                          value /= 10 ** 64;
                          result += 64;
                      }
                      if (value >= 10 ** 32) {
                          value /= 10 ** 32;
                          result += 32;
                      }
                      if (value >= 10 ** 16) {
                          value /= 10 ** 16;
                          result += 16;
                      }
                      if (value >= 10 ** 8) {
                          value /= 10 ** 8;
                          result += 8;
                      }
                      if (value >= 10 ** 4) {
                          value /= 10 ** 4;
                          result += 4;
                      }
                      if (value >= 10 ** 2) {
                          value /= 10 ** 2;
                          result += 2;
                      }
                      if (value >= 10 ** 1) {
                          result += 1;
                      }
                  }
                  return result;
              }
              /**
               * @dev Return the log in base 10, following the selected rounding direction, of a positive value.
               * Returns 0 if given 0.
               */
              function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
                  unchecked {
                      uint256 result = log10(value);
                      return result + (rounding == Rounding.Up && 10 ** result < value ? 1 : 0);
                  }
              }
              /**
               * @dev Return the log in base 256, rounded down, of a positive value.
               * Returns 0 if given 0.
               *
               * Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
               */
              function log256(uint256 value) internal pure returns (uint256) {
                  uint256 result = 0;
                  unchecked {
                      if (value >> 128 > 0) {
                          value >>= 128;
                          result += 16;
                      }
                      if (value >> 64 > 0) {
                          value >>= 64;
                          result += 8;
                      }
                      if (value >> 32 > 0) {
                          value >>= 32;
                          result += 4;
                      }
                      if (value >> 16 > 0) {
                          value >>= 16;
                          result += 2;
                      }
                      if (value >> 8 > 0) {
                          result += 1;
                      }
                  }
                  return result;
              }
              /**
               * @dev Return the log in base 256, following the selected rounding direction, of a positive value.
               * Returns 0 if given 0.
               */
              function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
                  unchecked {
                      uint256 result = log256(value);
                      return result + (rounding == Rounding.Up && 1 << (result << 3) < value ? 1 : 0);
                  }
              }
          }
          // SPDX-License-Identifier: LGPL-3.0 license 
          pragma solidity ^0.8.0;
          /// @title Multisignature wallet by TOZEX inspired by Gnosis Multisignature project for which we added new functionalities like transaction countdown validation and ERC20/ERC721/ERC1155 tokens management.
          /// @author Tozex company
          import "@openzeppelin/contracts-upgradeable/utils/math/MathUpgradeable.sol";
          import "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
          import "@openzeppelin/contracts-upgradeable/token/ERC20/IERC20Upgradeable.sol";
          import "@openzeppelin/contracts-upgradeable/token/ERC20/utils/SafeERC20Upgradeable.sol";
          import "@openzeppelin/contracts-upgradeable/token/ERC721/IERC721Upgradeable.sol";
          import "@openzeppelin/contracts-upgradeable/token/ERC721/IERC721ReceiverUpgradeable.sol";
          import "@openzeppelin/contracts-upgradeable/token/ERC1155/IERC1155Upgradeable.sol";
          import "@openzeppelin/contracts-upgradeable/token/ERC1155/utils/ERC1155ReceiverUpgradeable.sol";
          import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
           
          contract MultiSigWallet is 
            Initializable,
            OwnableUpgradeable, 
            IERC721ReceiverUpgradeable, 
            ERC1155ReceiverUpgradeable
          {
            using SafeERC20Upgradeable for IERC20Upgradeable;
            uint constant public MAX_OWNER_COUNT = 10;
            event Confirmation(address indexed sender, uint indexed transactionId);
            event Revocation(address indexed sender, uint indexed transactionId);
            event Submission(uint indexed transactionId);
            event Execution(uint indexed transactionId);
            event ExecutionFailure(uint indexed transactionId);
            event Deposit(address indexed sender, address indexed token, uint value);
            event ERC20Deposited(address indexed sender, address indexed token, uint value);
            event ERC721Deposited(address indexed sender, address indexed token, uint tokenId);
            event ERC1155Deposited(address indexed sender, address indexed token, uint tokenId, uint value);
            event SignerChangeRequested(address indexed currentSigner, address indexed newSigner);
            event SignerUpdated(address indexed oldSigner, address indexed newSigner);
            mapping(uint => Transaction) public transactions;
            mapping(uint => mapping(address => bool)) public confirmations;
            mapping(address => address) public signerChangeRequests;
            mapping(address => mapping(address => bool)) public signerChangeConfirmations;
            mapping(address => bool) public isSigner;
            address[] public signers;
            uint public required;
            uint public transactionCount;
            enum TokenStandard {
              ERC20,
              ERC721,
              ERC1155,
              USER
            }
            struct Transaction {
              bool executed;
              address payable destination;
              address token;
              bytes data;
              TokenStandard ts;
              uint tokenId;
              uint value;
              uint confirmTimestamp;
              uint txTimestamp;
            }
            modifier signerExists(address signer) {
              require(isSigner[signer], "Signer does not exist");
              _;
            }
            modifier transactionExists(uint transactionId) {
              require(transactions[transactionId].destination != address(0), "Transaction does not exist");
              _;
            }
            modifier confirmed(uint transactionId, address signer) {
              require(confirmations[transactionId][signer], "Transaction is not confirmed by the signer");
              _;
            }
            modifier notConfirmed(uint transactionId, address signer) {
              require(!confirmations[transactionId][signer], "Transaction already confirmed");
              _;
            }
            modifier notExecuted(uint transactionId) {
              require(!transactions[transactionId].executed, "Transaction already executed");
              _;
            }
            modifier notNull(address _address) {
              require(_address != address(0), "Address cannot be null");
              _;
            }
            modifier validRequirement(uint _signerCount, uint _required) {
              require(_signerCount <= MAX_OWNER_COUNT && required <= _signerCount && _required != 0 && _signerCount != 0, "Invalid requirement");
              _;
            }
            /** 
             * @dev Fallback function allows to deposit ether.
             */
            receive() external payable {
              if (msg.value > 0)
                emit Deposit(msg.sender, address(0), msg.value);
            }
            
            /**
             * Public functions
             * @dev Contract constructor sets initial signers and required number of confirmations.
             * @param _signers List of initial signers.
             * @param _required Number of required confirmations.
             */
            function initialize(address[] memory _signers, uint _required) external initializer validRequirement(_signers.length, _required) {
              __Ownable_init();
              
              for (uint i = 0; i < _signers.length; ) {
                require(!isSigner[_signers[i]] && _signers[i] != address(0) && _signers[i] != msg.sender, "Invalid signer");
                isSigner[_signers[i]] = true;
                unchecked {
                  i++;
                }
              }
              signers = _signers;
              required = _required;
            }
            /**
              * @dev Transfers ownership of the contract to a new account (`newOwner`).
              * Can only be called by the current owner.
              */
            function transferOwnership(address newOwner) public override virtual onlyOwner {
                require(!isSigner[newOwner], "Ownable: new owner cannot be signer.");
                super.transferOwnership(newOwner);
            }
            /** 
             * @notice Allows the owner to request a change of signer.
             * @param _oldSigner The address of the current signer to be replaced.
             * @param _newSigner The address of the new signer to be added.
             */
            function requestSignerChange(address _oldSigner, address _newSigner) external onlyOwner {
              require(isSigner[_oldSigner], "Old signer does not exist.");
              require(!isSigner[_newSigner], "New signer is already a signer.");
              require(_newSigner != owner(), "Onwer cannot be a signer.");
              
              // Clear the signerChangeConfirmations for _newSigner if a change is "in-progress"
              if (signerChangeRequests[_oldSigner] != address(0)) {
                  clearSignerChangeConfirmations(signerChangeRequests[_oldSigner]);
              }
              signerChangeRequests[_oldSigner] = _newSigner;
              emit SignerChangeRequested(_oldSigner, _newSigner);
            }
            /**
             * @notice Allows a signer to confirm a signer change requested by the owner.
             * @param _oldSigner The address of the current signer to be replaced.
             * @param _newSigner The address of the new signer to be added.
             */
            function confirmSignerChange(address _oldSigner, address _newSigner) external signerExists(msg.sender) {
              require(!signerChangeConfirmations[_newSigner][msg.sender], "You already confirmed.");
              require(signerChangeRequests[_oldSigner] == _newSigner, "New signer address invalid.");
              require(_newSigner != address(0), "No pending signer update request.");
              require(_newSigner != owner(), "Onwer cannot be a signer.");
              require(!isSigner[_newSigner], "New signer is already a signer.");
              // Confirm the update by the current signer
              signerChangeConfirmations[_newSigner][msg.sender] = true;
              
              if (isSignerChangeConfirmed(_newSigner)) {
                // Clear the signerChangeConfirmations for _newSigner
                clearSignerChangeConfirmations(_newSigner);
                signerChangeRequests[_oldSigner] = address(0);
                removeSigner(_oldSigner);
                isSigner[_newSigner] = true;
                signers.push(_newSigner);
                emit SignerUpdated(_oldSigner, _newSigner);
              }
            }
            function depositERC20(address token, uint amount) external {
              require(token != address(0) , "invalid token");
              require(amount > 0 , "invalid amount");
              IERC20Upgradeable(token).safeTransferFrom(msg.sender, address(this), amount);
              emit ERC20Deposited(msg.sender, token, amount); 
            }
            function depositERC721(address token, uint tokenId) external {
              // Transfer the ERC721 token to the multisig contract
              IERC721Upgradeable(token).safeTransferFrom(msg.sender, address(this), tokenId);
              emit ERC721Deposited(msg.sender, token, tokenId);
            }
            function depositERC1155(address token, uint tokenId, uint amount) external {
              // Transfer the ERC1155 tokens to the multisig contract
              IERC1155Upgradeable(token).safeTransferFrom(msg.sender, address(this), tokenId, amount, "");
              emit ERC1155Deposited(msg.sender, token, tokenId, amount);
            }
            /**
             * @dev Allows an signer to submit and confirm a transaction.
             * @param destination Transaction target address.
             * @param value Transaction ether value.
             * @param data Transaction data payload.
             */
            function submitTransaction(address payable destination, address token, TokenStandard ts, uint tokenId, uint value, bytes memory data, uint confirmTimestamp) public signerExists(msg.sender) returns (uint transactionId) {
              uint txTimestamp = _getNow();
              transactionId = addTransaction(destination, token, ts, tokenId, value, data, confirmTimestamp, txTimestamp);
              confirmTransaction(transactionId);
            }
           
            /**
             * @dev Allows an signer to confirm a transaction.
             * @param transactionId Transaction ID.
             */
            function confirmTransaction(uint transactionId) public signerExists(msg.sender) transactionExists(transactionId) notConfirmed(transactionId, msg.sender) {
              require(!isTransactionTimedOut(transactionId), "Transaction timed out.");
              confirmations[transactionId][msg.sender] = true;
              emit Confirmation(msg.sender, transactionId);
              executeTransaction(transactionId);
            }
            /**
             * @dev Returns the confirmation status of a transaction.
             * @param transactionId Transaction ID.
             */
            function isConfirmed(uint transactionId) public view returns (bool) {
              uint count = 0;
              mapping(address => bool) storage transactionConfirmations = confirmations[transactionId];
              uint256 signerCount = signers.length;
              for (uint i = 0; i < signerCount; ) {
                if (transactionConfirmations[signers[i]])
                  count += 1;
                if (count == required)
                  return true;
                
                unchecked {
                  i++;
                }
              }
              return false;
            }
            /**
             * Web3 call functions
             *
             * @dev Returns number of confirmations of a transaction.
             * @param transactionId Transaction ID.
             */
            function getConfirmationCount(uint transactionId) public view returns (uint count) {
              mapping(address => bool) storage transactionConfirmations = confirmations[transactionId];
              uint256 signerCount = signers.length;
              for (uint i = 0; i < signerCount; ) {
                if (transactionConfirmations[signers[i]])
                  count += 1;
                
                unchecked {
                  i++;
                }
              }
            }
            /**
             * @dev Returns total number of transactions after filers are applied.
             * @param pending Include pending transactions.
             * @param executed Include executed transactions.
             */
            function getTransactionCount(bool pending, bool executed) public view returns (uint count) {
              for (uint i = 0; i < transactionCount; ) {
                if ((pending && !transactions[i].executed && !isTransactionTimedOut(i)) || (executed && transactions[i].executed))
                  count += 1;
                unchecked {
                  i++;
                }
              }
            }
            /**
             * @dev Returns array with signer addresses, which confirmed transaction.
             * @param transactionId Transaction ID.
             */
            function getConfirmations(uint transactionId) public view returns (address[] memory _confirmations) {
              uint256 signerCount = signers.length;
              address[] memory confirmationsTemp = new address[](signerCount);
              mapping(address => bool) storage transactionConfirmations = confirmations[transactionId];
              uint count = 0;
              uint i;
              
              for (i = 0; i < signerCount; ) {
                if (transactionConfirmations[signers[i]]) {
                  confirmationsTemp[count] = signers[i];
                  count += 1;
                }
                unchecked {
                  i++;
                }
              }
              _confirmations = new address[](count);
              for (i = 0; i < count; ) {
                _confirmations[i] = confirmationsTemp[i];
                unchecked {
                  i++;
                }
              }
            }
            /**
             * @dev Returns list of transaction IDs in defined range.
             * @param from Index start position of transaction array.
             * @param to Index end position of transaction array.
             * @param pending Include pending transactions.
             * @param executed Include executed transactions.
             */
            function getTransactionIds(uint from, uint to, bool pending, bool executed) public view returns (uint[] memory _transactionIds)
            {
              require(from < to, "Invalid range: from must be less than to");
              from = MathUpgradeable.min(from, transactionCount);
              to = MathUpgradeable.max(to, transactionCount);
              
              uint[] memory transactionIdsTemp = new uint[](to - from);
              uint count = 0;
              for (uint i = from; i < to; ) {
                if ((pending && !transactions[i].executed && !isTransactionTimedOut(i))
                || (executed && transactions[i].executed))
                {
                  transactionIdsTemp[count] = i;
                  count += 1;
                }
                unchecked {
                  i++;
                }
              }
              _transactionIds = new uint[](count);
              for (uint i = 0; i < count; ) {
                _transactionIds[i] = transactionIdsTemp[i];
                unchecked {
                  i++;
                }
              }
            }
            /**
              * @dev See {IERC721Receiver-onERC721Received}.
              *
              * Always returns `IERC721Receiver.onERC721Received.selector`.
              */
            function onERC721Received(
                address,
                address,
                uint256,
                bytes memory
            ) public virtual override returns (bytes4) {
                return this.onERC721Received.selector;
            }
            function onERC1155Received(
                address,
                address,
                uint256,
                uint256,
                bytes memory
            ) public virtual override returns (bytes4) {
                return this.onERC1155Received.selector;
            }
            function onERC1155BatchReceived(
                address,
                address,
                uint256[] memory,
                uint256[] memory,
                bytes memory
            ) public virtual override returns (bytes4) {
                return this.onERC1155BatchReceived.selector;
            }
            
            /**
             * Internal functions
             *
             * @dev Adds a new transaction to the transaction mapping, if transaction does not exist yet.
             * @param destination Transaction target address.
             * @param value Transaction ether value.
             * @param data Transaction data payload.
             */
            function addTransaction(address payable destination, address token, TokenStandard ts, uint tokenId, uint value, bytes memory data, uint confirmTimestamp, uint txTimestamp) internal notNull(destination) returns (uint transactionId) {
              transactionId = transactionCount;
              transactions[transactionId] = Transaction({
                destination : destination,
                token: token,
                ts: ts,
                tokenId: tokenId,
                value : value,
                data : data,
                executed : false,
                confirmTimestamp : confirmTimestamp,
                txTimestamp : txTimestamp
                });
              transactionCount += 1;
              emit Submission(transactionId);
            }
            /**
             * @dev Allows anyone to execute a confirmed transaction.
             * @param transactionId Transaction ID.
             */
            function executeTransaction(uint transactionId) internal notExecuted(transactionId) {
              if (isConfirmed(transactionId)) {
                Transaction storage txn = transactions[transactionId];
                
                txn.executed = true;
                if(txn.ts == TokenStandard.USER) {
                  require(address(this).balance >= txn.value, "not enough amount to withdraw");
                  (bool transferSuccess,) =txn.destination.call{value: txn.value}(txn.data);
                  if (transferSuccess)
                    emit Execution(transactionId);
                  else {
                    emit ExecutionFailure(transactionId);
                    txn.executed = false;
                  }
                } else if(txn.ts == TokenStandard.ERC20) {
                  IERC20Upgradeable(txn.token).safeTransfer(txn.destination, txn.value);
                  emit Execution(transactionId);
                } else if(txn.ts == TokenStandard.ERC721) {
                  IERC721Upgradeable(txn.token).safeTransferFrom(address(this), txn.destination, txn.tokenId);
                  emit Execution(transactionId);
                } else if(txn.ts == TokenStandard.ERC1155) {
                  IERC1155Upgradeable(txn.token).safeTransferFrom(address(this), txn.destination, txn.tokenId, txn.value, "");
                  emit Execution(transactionId);
                }
              }
            }
            function isTransactionTimedOut(uint transactionId) internal view returns (bool) {
              Transaction storage transaction = transactions[transactionId];
              if(_getNow() < transaction.txTimestamp + transaction.confirmTimestamp || transaction.confirmTimestamp == 0) {
                return false;
              }
              return true;
            }
            function isSignerChangeConfirmed(address _newSigner) internal view returns (bool) {
              uint256 signerCount = signers.length;
              uint256 count;
              mapping(address => bool) storage confirmation = signerChangeConfirmations[_newSigner];
              for (uint i = 0; i < signerCount && count < required; ) {
                if (confirmation[signers[i]]) count ++;
                
                unchecked {
                  i++;
                }
              }
              return count == required;
            }
            function removeSigner(address oldSigner) internal {
              if (!isSigner[oldSigner]) return;
              uint256 signerCount = signers.length;
              for (uint i = 0; i < signerCount; ) {
                if (signers[i] == oldSigner) {
                    if (i != signerCount - 1) {
                      signers[i] = signers[signerCount - 1];
                    }
                    signers.pop();
                    isSigner[oldSigner] = false;
                    break;
                }
                unchecked {
                  i++;
                }
              }
            }
            function clearSignerChangeConfirmations(address _newSigner) internal {
              uint256 signerCount = signers.length;
              mapping(address => bool) storage confirmation = signerChangeConfirmations[_newSigner];
              for (uint i = 0; i < signerCount; ) {
                  confirmation[signers[i]] = false;
                  unchecked {
                    i++;
                  }
              }
            }
            function _getNow() internal view returns (uint256) {
                return block.timestamp;
            }
          }