ETH Price: $3,298.79 (-1.22%)

Transaction Decoder

Block:
17913719 at Aug-14-2023 02:35:23 PM +UTC
Transaction Fee:
0.003840950951920628 ETH $12.67
Gas Used:
124,579 Gas / 30.831447932 Gwei

Emitted Events:

238 0xfb941e7d4f5b1b976d5adf6e6d8bfe54841fc608.0x1bb9fb49058794ee4e0f88f3c95c10019922d0b1c6f27da1ee2a98ad19d9b308( 0x1bb9fb49058794ee4e0f88f3c95c10019922d0b1c6f27da1ee2a98ad19d9b308, 0x00000000000000000000000019c30ad5ea4f7f9f36a8662b5fa2cbc09e55fded, 000000000000000000000000000000000000000000000000016345785d8a0000 )
239 POW.Transfer( from=[Receiver] GnosisSafeProxy, to=0x000000000000000000000000000000000000dEaD, value=618980500000000000000000000 )
240 GnosisSafeProxy.0x442e715f626346e8c54381002da614f62bee8d27386535b2521ec8540898556e( 0x442e715f626346e8c54381002da614f62bee8d27386535b2521ec8540898556e, bb53b270dfd9f65fdd52e5b4a6ff6b0e4fec7c52fed10aa5a67a3ed100b10717, 0000000000000000000000000000000000000000000000000000000000000000 )

Account State Difference:

  Address   Before After State Difference Code
0x19C30Ad5...09E55FDED
(Pixel Vault: UPDAO Treasury)
7,819.8425 Eth7,819.7425 Eth0.1
0.324736946093382986 Eth0.324923814593382986 Eth0.0001868685
0x267be1C1...41E4Ffdc0
(Kraken 4)
60,469.567805124373079085 Eth60,469.667805124373079085 Eth0.1
0x43Ab765e...CA3079258
0xb21b7D5B...B6D08E860
(Decisions, Upsets and Unknowns.: Deployer)
0.892020128538504963 Eth
Nonce: 248
0.888179177586584335 Eth
Nonce: 249
0.003840950951920628

Execution Trace

GnosisSafeProxy.6a761202( )
  • GnosisSafe.execTransaction( to=0x40A2aCCbd92BCA938b02010E17A5b8929b49130D, value=0, data=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, operation=1, safeTxGas=0, baseGas=0, gasPrice=0, gasToken=0x0000000000000000000000000000000000000000, refundReceiver=0x0000000000000000000000000000000000000000, signatures=0x9B16A1060C9425B77629EA186A4E880FA1D6F9F591364169AF0F7536406E9DD311CF4AB4CD8A80A46BFA88C5B5EA3C7A1B151DAEBFC55BE9D1815EED87FD65621C000000000000000000000000B21B7D5B3F348930EC6AA2D4135217BB6D08E860000000000000000000000000000000000000000000000000000000000000000001 ) => ( success=True )
    • Null: 0x000...001.bb53b270( )
    • MultiSendCallOnly.multiSend( transactions=0x00FB941E7D4F5B1B976D5ADF6E6D8BFE54841FC608000000000000000000000000000000000000000000000000016345785D8A000000000000000000000000000000000000000000000000000000000000000000000043AB765EE05075D78AD8AA79DCB1978CA307925800000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000044A9059CBB000000000000000000000000000000000000000000000000000000000000DEAD000000000000000000000000000000000000000002000238242CC601D5D00000 )
      • ETH 0.1 0xfb941e7d4f5b1b976d5adf6e6d8bfe54841fc608.CALL( )
        • ETH 0.1 0xd332254f274cc65aa11178b74734e2992b8f349e.DELEGATECALL( )
          • Kraken: Deployer 2.STATICCALL( )
            • 0x2febe3d60bb2bbdab135c740617241c2eb949635.DELEGATECALL( )
            • ETH 0.1 0xa435eafb97796f07b80f94cb8bd60a18b7efb985.DELEGATECALL( )
              • ETH 0.1 Kraken 4.CALL( )
              • POW.transfer( recipient=0x000000000000000000000000000000000000dEaD, amount=618980500000000000000000000 ) => ( True )
                File 1 of 4: GnosisSafeProxy
                // SPDX-License-Identifier: LGPL-3.0-only
                pragma solidity >=0.7.0 <0.9.0;
                
                /// @title IProxy - Helper interface to access masterCopy of the Proxy on-chain
                /// @author Richard Meissner - <[email protected]>
                interface IProxy {
                    function masterCopy() external view returns (address);
                }
                
                /// @title GnosisSafeProxy - Generic proxy contract allows to execute all transactions applying the code of a master contract.
                /// @author Stefan George - <[email protected]>
                /// @author Richard Meissner - <[email protected]>
                contract GnosisSafeProxy {
                    // singleton always needs to be first declared variable, to ensure that it is at the same location in the contracts to which calls are delegated.
                    // To reduce deployment costs this variable is internal and needs to be retrieved via `getStorageAt`
                    address internal singleton;
                
                    /// @dev Constructor function sets address of singleton contract.
                    /// @param _singleton Singleton address.
                    constructor(address _singleton) {
                        require(_singleton != address(0), "Invalid singleton address provided");
                        singleton = _singleton;
                    }
                
                    /// @dev Fallback function forwards all transactions and returns all received return data.
                    fallback() external payable {
                        // solhint-disable-next-line no-inline-assembly
                        assembly {
                            let _singleton := and(sload(0), 0xffffffffffffffffffffffffffffffffffffffff)
                            // 0xa619486e == keccak("masterCopy()"). The value is right padded to 32-bytes with 0s
                            if eq(calldataload(0), 0xa619486e00000000000000000000000000000000000000000000000000000000) {
                                mstore(0, _singleton)
                                return(0, 0x20)
                            }
                            calldatacopy(0, 0, calldatasize())
                            let success := delegatecall(gas(), _singleton, 0, calldatasize(), 0, 0)
                            returndatacopy(0, 0, returndatasize())
                            if eq(success, 0) {
                                revert(0, returndatasize())
                            }
                            return(0, returndatasize())
                        }
                    }
                }
                
                /// @title Proxy Factory - Allows to create new proxy contact and execute a message call to the new proxy within one transaction.
                /// @author Stefan George - <[email protected]>
                contract GnosisSafeProxyFactory {
                    event ProxyCreation(GnosisSafeProxy proxy, address singleton);
                
                    /// @dev Allows to create new proxy contact and execute a message call to the new proxy within one transaction.
                    /// @param singleton Address of singleton contract.
                    /// @param data Payload for message call sent to new proxy contract.
                    function createProxy(address singleton, bytes memory data) public returns (GnosisSafeProxy proxy) {
                        proxy = new GnosisSafeProxy(singleton);
                        if (data.length > 0)
                            // solhint-disable-next-line no-inline-assembly
                            assembly {
                                if eq(call(gas(), proxy, 0, add(data, 0x20), mload(data), 0, 0), 0) {
                                    revert(0, 0)
                                }
                            }
                        emit ProxyCreation(proxy, singleton);
                    }
                
                    /// @dev Allows to retrieve the runtime code of a deployed Proxy. This can be used to check that the expected Proxy was deployed.
                    function proxyRuntimeCode() public pure returns (bytes memory) {
                        return type(GnosisSafeProxy).runtimeCode;
                    }
                
                    /// @dev Allows to retrieve the creation code used for the Proxy deployment. With this it is easily possible to calculate predicted address.
                    function proxyCreationCode() public pure returns (bytes memory) {
                        return type(GnosisSafeProxy).creationCode;
                    }
                
                    /// @dev Allows to create new proxy contact using CREATE2 but it doesn't run the initializer.
                    ///      This method is only meant as an utility to be called from other methods
                    /// @param _singleton Address of singleton contract.
                    /// @param initializer Payload for message call sent to new proxy contract.
                    /// @param saltNonce Nonce that will be used to generate the salt to calculate the address of the new proxy contract.
                    function deployProxyWithNonce(
                        address _singleton,
                        bytes memory initializer,
                        uint256 saltNonce
                    ) internal returns (GnosisSafeProxy proxy) {
                        // If the initializer changes the proxy address should change too. Hashing the initializer data is cheaper than just concatinating it
                        bytes32 salt = keccak256(abi.encodePacked(keccak256(initializer), saltNonce));
                        bytes memory deploymentData = abi.encodePacked(type(GnosisSafeProxy).creationCode, uint256(uint160(_singleton)));
                        // solhint-disable-next-line no-inline-assembly
                        assembly {
                            proxy := create2(0x0, add(0x20, deploymentData), mload(deploymentData), salt)
                        }
                        require(address(proxy) != address(0), "Create2 call failed");
                    }
                
                    /// @dev Allows to create new proxy contact and execute a message call to the new proxy within one transaction.
                    /// @param _singleton Address of singleton contract.
                    /// @param initializer Payload for message call sent to new proxy contract.
                    /// @param saltNonce Nonce that will be used to generate the salt to calculate the address of the new proxy contract.
                    function createProxyWithNonce(
                        address _singleton,
                        bytes memory initializer,
                        uint256 saltNonce
                    ) public returns (GnosisSafeProxy proxy) {
                        proxy = deployProxyWithNonce(_singleton, initializer, saltNonce);
                        if (initializer.length > 0)
                            // solhint-disable-next-line no-inline-assembly
                            assembly {
                                if eq(call(gas(), proxy, 0, add(initializer, 0x20), mload(initializer), 0, 0), 0) {
                                    revert(0, 0)
                                }
                            }
                        emit ProxyCreation(proxy, _singleton);
                    }
                
                    /// @dev Allows to create new proxy contact, execute a message call to the new proxy and call a specified callback within one transaction
                    /// @param _singleton Address of singleton contract.
                    /// @param initializer Payload for message call sent to new proxy contract.
                    /// @param saltNonce Nonce that will be used to generate the salt to calculate the address of the new proxy contract.
                    /// @param callback Callback that will be invoced after the new proxy contract has been successfully deployed and initialized.
                    function createProxyWithCallback(
                        address _singleton,
                        bytes memory initializer,
                        uint256 saltNonce,
                        IProxyCreationCallback callback
                    ) public returns (GnosisSafeProxy proxy) {
                        uint256 saltNonceWithCallback = uint256(keccak256(abi.encodePacked(saltNonce, callback)));
                        proxy = createProxyWithNonce(_singleton, initializer, saltNonceWithCallback);
                        if (address(callback) != address(0)) callback.proxyCreated(proxy, _singleton, initializer, saltNonce);
                    }
                
                    /// @dev Allows to get the address for a new proxy contact created via `createProxyWithNonce`
                    ///      This method is only meant for address calculation purpose when you use an initializer that would revert,
                    ///      therefore the response is returned with a revert. When calling this method set `from` to the address of the proxy factory.
                    /// @param _singleton Address of singleton contract.
                    /// @param initializer Payload for message call sent to new proxy contract.
                    /// @param saltNonce Nonce that will be used to generate the salt to calculate the address of the new proxy contract.
                    function calculateCreateProxyWithNonceAddress(
                        address _singleton,
                        bytes calldata initializer,
                        uint256 saltNonce
                    ) external returns (GnosisSafeProxy proxy) {
                        proxy = deployProxyWithNonce(_singleton, initializer, saltNonce);
                        revert(string(abi.encodePacked(proxy)));
                    }
                }
                
                interface IProxyCreationCallback {
                    function proxyCreated(
                        GnosisSafeProxy proxy,
                        address _singleton,
                        bytes calldata initializer,
                        uint256 saltNonce
                    ) external;
                }

                File 2 of 4: POW
                // SPDX-License-Identifier: MIT
                pragma solidity ^0.8.4;
                import '@openzeppelin/contracts/token/ERC20/extensions/ERC20Burnable.sol';
                import "@openzeppelin/contracts/access/Ownable.sol";
                contract POW is ERC20Burnable {
                    constructor(
                        string memory name,
                        string memory symbol,
                        uint256 initialSupply,
                        address receiver
                    ) ERC20(name, symbol) {
                        _mint(receiver, initialSupply);
                    }
                }
                // SPDX-License-Identifier: MIT
                pragma solidity ^0.8.0;
                import "../ERC20.sol";
                import "../../../utils/Context.sol";
                /**
                 * @dev Extension of {ERC20} that allows token holders to destroy both their own
                 * tokens and those that they have an allowance for, in a way that can be
                 * recognized off-chain (via event analysis).
                 */
                abstract contract ERC20Burnable is Context, ERC20 {
                    /**
                     * @dev Destroys `amount` tokens from the caller.
                     *
                     * See {ERC20-_burn}.
                     */
                    function burn(uint256 amount) public virtual {
                        _burn(_msgSender(), amount);
                    }
                    /**
                     * @dev Destroys `amount` tokens from `account`, deducting from the caller's
                     * allowance.
                     *
                     * See {ERC20-_burn} and {ERC20-allowance}.
                     *
                     * Requirements:
                     *
                     * - the caller must have allowance for ``accounts``'s tokens of at least
                     * `amount`.
                     */
                    function burnFrom(address account, uint256 amount) public virtual {
                        uint256 currentAllowance = allowance(account, _msgSender());
                        require(currentAllowance >= amount, "ERC20: burn amount exceeds allowance");
                        unchecked {
                            _approve(account, _msgSender(), currentAllowance - amount);
                        }
                        _burn(account, amount);
                    }
                }
                // SPDX-License-Identifier: MIT
                pragma solidity ^0.8.0;
                import "../utils/Context.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 Ownable is Context {
                    address private _owner;
                    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
                    /**
                     * @dev Initializes the contract setting the deployer as the initial owner.
                     */
                    constructor() {
                        _setOwner(_msgSender());
                    }
                    /**
                     * @dev Returns the address of the current owner.
                     */
                    function owner() public view virtual returns (address) {
                        return _owner;
                    }
                    /**
                     * @dev Throws if called by any account other than the owner.
                     */
                    modifier onlyOwner() {
                        require(owner() == _msgSender(), "Ownable: caller is not the owner");
                        _;
                    }
                    /**
                     * @dev Leaves the contract without owner. It will not be possible to call
                     * `onlyOwner` functions anymore. Can only be called by the current owner.
                     *
                     * NOTE: Renouncing ownership will leave the contract without an owner,
                     * thereby removing any functionality that is only available to the owner.
                     */
                    function renounceOwnership() public virtual onlyOwner {
                        _setOwner(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");
                        _setOwner(newOwner);
                    }
                    function _setOwner(address newOwner) private {
                        address oldOwner = _owner;
                        _owner = newOwner;
                        emit OwnershipTransferred(oldOwner, newOwner);
                    }
                }
                // SPDX-License-Identifier: MIT
                pragma solidity ^0.8.0;
                import "./IERC20.sol";
                import "./extensions/IERC20Metadata.sol";
                import "../../utils/Context.sol";
                /**
                 * @dev Implementation of the {IERC20} interface.
                 *
                 * This implementation is agnostic to the way tokens are created. This means
                 * that a supply mechanism has to be added in a derived contract using {_mint}.
                 * For a generic mechanism see {ERC20PresetMinterPauser}.
                 *
                 * TIP: For a detailed writeup see our guide
                 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
                 * to implement supply mechanisms].
                 *
                 * We have followed general OpenZeppelin guidelines: functions revert instead
                 * of returning `false` on failure. This behavior is nonetheless conventional
                 * and does not conflict with the expectations of ERC20 applications.
                 *
                 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
                 * This allows applications to reconstruct the allowance for all accounts just
                 * by listening to said events. Other implementations of the EIP may not emit
                 * these events, as it isn't required by the specification.
                 *
                 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
                 * functions have been added to mitigate the well-known issues around setting
                 * allowances. See {IERC20-approve}.
                 */
                contract ERC20 is Context, IERC20, IERC20Metadata {
                    mapping(address => uint256) private _balances;
                    mapping(address => mapping(address => uint256)) private _allowances;
                    uint256 private _totalSupply;
                    string private _name;
                    string private _symbol;
                    /**
                     * @dev Sets the values for {name} and {symbol}.
                     *
                     * The default value of {decimals} is 18. To select a different value for
                     * {decimals} you should overload it.
                     *
                     * All two of these values are immutable: they can only be set once during
                     * construction.
                     */
                    constructor(string memory name_, string memory symbol_) {
                        _name = name_;
                        _symbol = symbol_;
                    }
                    /**
                     * @dev Returns the name of the token.
                     */
                    function name() public view virtual override returns (string memory) {
                        return _name;
                    }
                    /**
                     * @dev Returns the symbol of the token, usually a shorter version of the
                     * name.
                     */
                    function symbol() public view virtual override returns (string memory) {
                        return _symbol;
                    }
                    /**
                     * @dev Returns the number of decimals used to get its user representation.
                     * For example, if `decimals` equals `2`, a balance of `505` tokens should
                     * be displayed to a user as `5,05` (`505 / 10 ** 2`).
                     *
                     * Tokens usually opt for a value of 18, imitating the relationship between
                     * Ether and Wei. This is the value {ERC20} uses, unless this function is
                     * overridden;
                     *
                     * NOTE: This information is only used for _display_ purposes: it in
                     * no way affects any of the arithmetic of the contract, including
                     * {IERC20-balanceOf} and {IERC20-transfer}.
                     */
                    function decimals() public view virtual override returns (uint8) {
                        return 18;
                    }
                    /**
                     * @dev See {IERC20-totalSupply}.
                     */
                    function totalSupply() public view virtual override returns (uint256) {
                        return _totalSupply;
                    }
                    /**
                     * @dev See {IERC20-balanceOf}.
                     */
                    function balanceOf(address account) public view virtual override returns (uint256) {
                        return _balances[account];
                    }
                    /**
                     * @dev See {IERC20-transfer}.
                     *
                     * Requirements:
                     *
                     * - `recipient` cannot be the zero address.
                     * - the caller must have a balance of at least `amount`.
                     */
                    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
                        _transfer(_msgSender(), recipient, amount);
                        return true;
                    }
                    /**
                     * @dev See {IERC20-allowance}.
                     */
                    function allowance(address owner, address spender) public view virtual override returns (uint256) {
                        return _allowances[owner][spender];
                    }
                    /**
                     * @dev See {IERC20-approve}.
                     *
                     * Requirements:
                     *
                     * - `spender` cannot be the zero address.
                     */
                    function approve(address spender, uint256 amount) public virtual override returns (bool) {
                        _approve(_msgSender(), spender, amount);
                        return true;
                    }
                    /**
                     * @dev See {IERC20-transferFrom}.
                     *
                     * Emits an {Approval} event indicating the updated allowance. This is not
                     * required by the EIP. See the note at the beginning of {ERC20}.
                     *
                     * Requirements:
                     *
                     * - `sender` and `recipient` cannot be the zero address.
                     * - `sender` must have a balance of at least `amount`.
                     * - the caller must have allowance for ``sender``'s tokens of at least
                     * `amount`.
                     */
                    function transferFrom(
                        address sender,
                        address recipient,
                        uint256 amount
                    ) public virtual override returns (bool) {
                        _transfer(sender, recipient, amount);
                        uint256 currentAllowance = _allowances[sender][_msgSender()];
                        require(currentAllowance >= amount, "ERC20: transfer amount exceeds allowance");
                        unchecked {
                            _approve(sender, _msgSender(), currentAllowance - amount);
                        }
                        return true;
                    }
                    /**
                     * @dev Atomically increases the allowance granted to `spender` by the caller.
                     *
                     * This is an alternative to {approve} that can be used as a mitigation for
                     * problems described in {IERC20-approve}.
                     *
                     * Emits an {Approval} event indicating the updated allowance.
                     *
                     * Requirements:
                     *
                     * - `spender` cannot be the zero address.
                     */
                    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
                        _approve(_msgSender(), spender, _allowances[_msgSender()][spender] + addedValue);
                        return true;
                    }
                    /**
                     * @dev Atomically decreases the allowance granted to `spender` by the caller.
                     *
                     * This is an alternative to {approve} that can be used as a mitigation for
                     * problems described in {IERC20-approve}.
                     *
                     * Emits an {Approval} event indicating the updated allowance.
                     *
                     * Requirements:
                     *
                     * - `spender` cannot be the zero address.
                     * - `spender` must have allowance for the caller of at least
                     * `subtractedValue`.
                     */
                    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
                        uint256 currentAllowance = _allowances[_msgSender()][spender];
                        require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
                        unchecked {
                            _approve(_msgSender(), spender, currentAllowance - subtractedValue);
                        }
                        return true;
                    }
                    /**
                     * @dev Moves `amount` of tokens from `sender` to `recipient`.
                     *
                     * This internal function is equivalent to {transfer}, and can be used to
                     * e.g. implement automatic token fees, slashing mechanisms, etc.
                     *
                     * Emits a {Transfer} event.
                     *
                     * Requirements:
                     *
                     * - `sender` cannot be the zero address.
                     * - `recipient` cannot be the zero address.
                     * - `sender` must have a balance of at least `amount`.
                     */
                    function _transfer(
                        address sender,
                        address recipient,
                        uint256 amount
                    ) internal virtual {
                        require(sender != address(0), "ERC20: transfer from the zero address");
                        require(recipient != address(0), "ERC20: transfer to the zero address");
                        _beforeTokenTransfer(sender, recipient, amount);
                        uint256 senderBalance = _balances[sender];
                        require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
                        unchecked {
                            _balances[sender] = senderBalance - amount;
                        }
                        _balances[recipient] += amount;
                        emit Transfer(sender, recipient, amount);
                        _afterTokenTransfer(sender, recipient, amount);
                    }
                    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
                     * the total supply.
                     *
                     * Emits a {Transfer} event with `from` set to the zero address.
                     *
                     * Requirements:
                     *
                     * - `account` cannot be the zero address.
                     */
                    function _mint(address account, uint256 amount) internal virtual {
                        require(account != address(0), "ERC20: mint to the zero address");
                        _beforeTokenTransfer(address(0), account, amount);
                        _totalSupply += amount;
                        _balances[account] += amount;
                        emit Transfer(address(0), account, amount);
                        _afterTokenTransfer(address(0), account, amount);
                    }
                    /**
                     * @dev Destroys `amount` tokens from `account`, reducing the
                     * total supply.
                     *
                     * Emits a {Transfer} event with `to` set to the zero address.
                     *
                     * Requirements:
                     *
                     * - `account` cannot be the zero address.
                     * - `account` must have at least `amount` tokens.
                     */
                    function _burn(address account, uint256 amount) internal virtual {
                        require(account != address(0), "ERC20: burn from the zero address");
                        _beforeTokenTransfer(account, address(0), amount);
                        uint256 accountBalance = _balances[account];
                        require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
                        unchecked {
                            _balances[account] = accountBalance - amount;
                        }
                        _totalSupply -= amount;
                        emit Transfer(account, address(0), amount);
                        _afterTokenTransfer(account, address(0), amount);
                    }
                    /**
                     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
                     *
                     * This internal function is equivalent to `approve`, and can be used to
                     * e.g. set automatic allowances for certain subsystems, etc.
                     *
                     * Emits an {Approval} event.
                     *
                     * Requirements:
                     *
                     * - `owner` cannot be the zero address.
                     * - `spender` cannot be the zero address.
                     */
                    function _approve(
                        address owner,
                        address spender,
                        uint256 amount
                    ) internal virtual {
                        require(owner != address(0), "ERC20: approve from the zero address");
                        require(spender != address(0), "ERC20: approve to the zero address");
                        _allowances[owner][spender] = amount;
                        emit Approval(owner, spender, amount);
                    }
                    /**
                     * @dev Hook that is called before any transfer of tokens. This includes
                     * minting and burning.
                     *
                     * Calling conditions:
                     *
                     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
                     * will be transferred to `to`.
                     * - when `from` is zero, `amount` tokens will be minted for `to`.
                     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
                     * - `from` and `to` are never both zero.
                     *
                     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
                     */
                    function _beforeTokenTransfer(
                        address from,
                        address to,
                        uint256 amount
                    ) internal virtual {}
                    /**
                     * @dev Hook that is called after any transfer of tokens. This includes
                     * minting and burning.
                     *
                     * Calling conditions:
                     *
                     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
                     * has been transferred to `to`.
                     * - when `from` is zero, `amount` tokens have been minted for `to`.
                     * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
                     * - `from` and `to` are never both zero.
                     *
                     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
                     */
                    function _afterTokenTransfer(
                        address from,
                        address to,
                        uint256 amount
                    ) internal virtual {}
                }
                // SPDX-License-Identifier: MIT
                pragma solidity ^0.8.0;
                /*
                 * @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 Context {
                    function _msgSender() internal view virtual returns (address) {
                        return msg.sender;
                    }
                    function _msgData() internal view virtual returns (bytes calldata) {
                        return msg.data;
                    }
                }
                // SPDX-License-Identifier: MIT
                pragma solidity ^0.8.0;
                /**
                 * @dev Interface of the ERC20 standard as defined in the EIP.
                 */
                interface IERC20 {
                    /**
                     * @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 `recipient`.
                     *
                     * Returns a boolean value indicating whether the operation succeeded.
                     *
                     * Emits a {Transfer} event.
                     */
                    function transfer(address recipient, 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 `sender` to `recipient` 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 sender,
                        address recipient,
                        uint256 amount
                    ) external returns (bool);
                    /**
                     * @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);
                }
                // SPDX-License-Identifier: MIT
                pragma solidity ^0.8.0;
                import "../IERC20.sol";
                /**
                 * @dev Interface for the optional metadata functions from the ERC20 standard.
                 *
                 * _Available since v4.1._
                 */
                interface IERC20Metadata is IERC20 {
                    /**
                     * @dev Returns the name of the token.
                     */
                    function name() external view returns (string memory);
                    /**
                     * @dev Returns the symbol of the token.
                     */
                    function symbol() external view returns (string memory);
                    /**
                     * @dev Returns the decimals places of the token.
                     */
                    function decimals() external view returns (uint8);
                }
                

                File 3 of 4: GnosisSafe
                // SPDX-License-Identifier: LGPL-3.0-only
                pragma solidity >=0.7.0 <0.9.0;
                import "./base/ModuleManager.sol";
                import "./base/OwnerManager.sol";
                import "./base/FallbackManager.sol";
                import "./base/GuardManager.sol";
                import "./common/EtherPaymentFallback.sol";
                import "./common/Singleton.sol";
                import "./common/SignatureDecoder.sol";
                import "./common/SecuredTokenTransfer.sol";
                import "./common/StorageAccessible.sol";
                import "./interfaces/ISignatureValidator.sol";
                import "./external/GnosisSafeMath.sol";
                /// @title Gnosis Safe - A multisignature wallet with support for confirmations using signed messages based on ERC191.
                /// @author Stefan George - <[email protected]>
                /// @author Richard Meissner - <[email protected]>
                contract GnosisSafe is
                    EtherPaymentFallback,
                    Singleton,
                    ModuleManager,
                    OwnerManager,
                    SignatureDecoder,
                    SecuredTokenTransfer,
                    ISignatureValidatorConstants,
                    FallbackManager,
                    StorageAccessible,
                    GuardManager
                {
                    using GnosisSafeMath for uint256;
                    string public constant VERSION = "1.3.0";
                    // keccak256(
                    //     "EIP712Domain(uint256 chainId,address verifyingContract)"
                    // );
                    bytes32 private constant DOMAIN_SEPARATOR_TYPEHASH = 0x47e79534a245952e8b16893a336b85a3d9ea9fa8c573f3d803afb92a79469218;
                    // keccak256(
                    //     "SafeTx(address to,uint256 value,bytes data,uint8 operation,uint256 safeTxGas,uint256 baseGas,uint256 gasPrice,address gasToken,address refundReceiver,uint256 nonce)"
                    // );
                    bytes32 private constant SAFE_TX_TYPEHASH = 0xbb8310d486368db6bd6f849402fdd73ad53d316b5a4b2644ad6efe0f941286d8;
                    event SafeSetup(address indexed initiator, address[] owners, uint256 threshold, address initializer, address fallbackHandler);
                    event ApproveHash(bytes32 indexed approvedHash, address indexed owner);
                    event SignMsg(bytes32 indexed msgHash);
                    event ExecutionFailure(bytes32 txHash, uint256 payment);
                    event ExecutionSuccess(bytes32 txHash, uint256 payment);
                    uint256 public nonce;
                    bytes32 private _deprecatedDomainSeparator;
                    // Mapping to keep track of all message hashes that have been approve by ALL REQUIRED owners
                    mapping(bytes32 => uint256) public signedMessages;
                    // Mapping to keep track of all hashes (message or transaction) that have been approve by ANY owners
                    mapping(address => mapping(bytes32 => uint256)) public approvedHashes;
                    // This constructor ensures that this contract can only be used as a master copy for Proxy contracts
                    constructor() {
                        // By setting the threshold it is not possible to call setup anymore,
                        // so we create a Safe with 0 owners and threshold 1.
                        // This is an unusable Safe, perfect for the singleton
                        threshold = 1;
                    }
                    /// @dev Setup function sets initial storage of contract.
                    /// @param _owners List of Safe owners.
                    /// @param _threshold Number of required confirmations for a Safe transaction.
                    /// @param to Contract address for optional delegate call.
                    /// @param data Data payload for optional delegate call.
                    /// @param fallbackHandler Handler for fallback calls to this contract
                    /// @param paymentToken Token that should be used for the payment (0 is ETH)
                    /// @param payment Value that should be paid
                    /// @param paymentReceiver Adddress that should receive the payment (or 0 if tx.origin)
                    function setup(
                        address[] calldata _owners,
                        uint256 _threshold,
                        address to,
                        bytes calldata data,
                        address fallbackHandler,
                        address paymentToken,
                        uint256 payment,
                        address payable paymentReceiver
                    ) external {
                        // setupOwners checks if the Threshold is already set, therefore preventing that this method is called twice
                        setupOwners(_owners, _threshold);
                        if (fallbackHandler != address(0)) internalSetFallbackHandler(fallbackHandler);
                        // As setupOwners can only be called if the contract has not been initialized we don't need a check for setupModules
                        setupModules(to, data);
                        if (payment > 0) {
                            // To avoid running into issues with EIP-170 we reuse the handlePayment function (to avoid adjusting code of that has been verified we do not adjust the method itself)
                            // baseGas = 0, gasPrice = 1 and gas = payment => amount = (payment + 0) * 1 = payment
                            handlePayment(payment, 0, 1, paymentToken, paymentReceiver);
                        }
                        emit SafeSetup(msg.sender, _owners, _threshold, to, fallbackHandler);
                    }
                    /// @dev Allows to execute a Safe transaction confirmed by required number of owners and then pays the account that submitted the transaction.
                    ///      Note: The fees are always transferred, even if the user transaction fails.
                    /// @param to Destination address of Safe transaction.
                    /// @param value Ether value of Safe transaction.
                    /// @param data Data payload of Safe transaction.
                    /// @param operation Operation type of Safe transaction.
                    /// @param safeTxGas Gas that should be used for the Safe transaction.
                    /// @param baseGas Gas costs that are independent of the transaction execution(e.g. base transaction fee, signature check, payment of the refund)
                    /// @param gasPrice Gas price that should be used for the payment calculation.
                    /// @param gasToken Token address (or 0 if ETH) that is used for the payment.
                    /// @param refundReceiver Address of receiver of gas payment (or 0 if tx.origin).
                    /// @param signatures Packed signature data ({bytes32 r}{bytes32 s}{uint8 v})
                    function execTransaction(
                        address to,
                        uint256 value,
                        bytes calldata data,
                        Enum.Operation operation,
                        uint256 safeTxGas,
                        uint256 baseGas,
                        uint256 gasPrice,
                        address gasToken,
                        address payable refundReceiver,
                        bytes memory signatures
                    ) public payable virtual returns (bool success) {
                        bytes32 txHash;
                        // Use scope here to limit variable lifetime and prevent `stack too deep` errors
                        {
                            bytes memory txHashData =
                                encodeTransactionData(
                                    // Transaction info
                                    to,
                                    value,
                                    data,
                                    operation,
                                    safeTxGas,
                                    // Payment info
                                    baseGas,
                                    gasPrice,
                                    gasToken,
                                    refundReceiver,
                                    // Signature info
                                    nonce
                                );
                            // Increase nonce and execute transaction.
                            nonce++;
                            txHash = keccak256(txHashData);
                            checkSignatures(txHash, txHashData, signatures);
                        }
                        address guard = getGuard();
                        {
                            if (guard != address(0)) {
                                Guard(guard).checkTransaction(
                                    // Transaction info
                                    to,
                                    value,
                                    data,
                                    operation,
                                    safeTxGas,
                                    // Payment info
                                    baseGas,
                                    gasPrice,
                                    gasToken,
                                    refundReceiver,
                                    // Signature info
                                    signatures,
                                    msg.sender
                                );
                            }
                        }
                        // We require some gas to emit the events (at least 2500) after the execution and some to perform code until the execution (500)
                        // We also include the 1/64 in the check that is not send along with a call to counteract potential shortings because of EIP-150
                        require(gasleft() >= ((safeTxGas * 64) / 63).max(safeTxGas + 2500) + 500, "GS010");
                        // Use scope here to limit variable lifetime and prevent `stack too deep` errors
                        {
                            uint256 gasUsed = gasleft();
                            // If the gasPrice is 0 we assume that nearly all available gas can be used (it is always more than safeTxGas)
                            // We only substract 2500 (compared to the 3000 before) to ensure that the amount passed is still higher than safeTxGas
                            success = execute(to, value, data, operation, gasPrice == 0 ? (gasleft() - 2500) : safeTxGas);
                            gasUsed = gasUsed.sub(gasleft());
                            // If no safeTxGas and no gasPrice was set (e.g. both are 0), then the internal tx is required to be successful
                            // This makes it possible to use `estimateGas` without issues, as it searches for the minimum gas where the tx doesn't revert
                            require(success || safeTxGas != 0 || gasPrice != 0, "GS013");
                            // We transfer the calculated tx costs to the tx.origin to avoid sending it to intermediate contracts that have made calls
                            uint256 payment = 0;
                            if (gasPrice > 0) {
                                payment = handlePayment(gasUsed, baseGas, gasPrice, gasToken, refundReceiver);
                            }
                            if (success) emit ExecutionSuccess(txHash, payment);
                            else emit ExecutionFailure(txHash, payment);
                        }
                        {
                            if (guard != address(0)) {
                                Guard(guard).checkAfterExecution(txHash, success);
                            }
                        }
                    }
                    function handlePayment(
                        uint256 gasUsed,
                        uint256 baseGas,
                        uint256 gasPrice,
                        address gasToken,
                        address payable refundReceiver
                    ) private returns (uint256 payment) {
                        // solhint-disable-next-line avoid-tx-origin
                        address payable receiver = refundReceiver == address(0) ? payable(tx.origin) : refundReceiver;
                        if (gasToken == address(0)) {
                            // For ETH we will only adjust the gas price to not be higher than the actual used gas price
                            payment = gasUsed.add(baseGas).mul(gasPrice < tx.gasprice ? gasPrice : tx.gasprice);
                            require(receiver.send(payment), "GS011");
                        } else {
                            payment = gasUsed.add(baseGas).mul(gasPrice);
                            require(transferToken(gasToken, receiver, payment), "GS012");
                        }
                    }
                    /**
                     * @dev Checks whether the signature provided is valid for the provided data, hash. Will revert otherwise.
                     * @param dataHash Hash of the data (could be either a message hash or transaction hash)
                     * @param data That should be signed (this is passed to an external validator contract)
                     * @param signatures Signature data that should be verified. Can be ECDSA signature, contract signature (EIP-1271) or approved hash.
                     */
                    function checkSignatures(
                        bytes32 dataHash,
                        bytes memory data,
                        bytes memory signatures
                    ) public view {
                        // Load threshold to avoid multiple storage loads
                        uint256 _threshold = threshold;
                        // Check that a threshold is set
                        require(_threshold > 0, "GS001");
                        checkNSignatures(dataHash, data, signatures, _threshold);
                    }
                    /**
                     * @dev Checks whether the signature provided is valid for the provided data, hash. Will revert otherwise.
                     * @param dataHash Hash of the data (could be either a message hash or transaction hash)
                     * @param data That should be signed (this is passed to an external validator contract)
                     * @param signatures Signature data that should be verified. Can be ECDSA signature, contract signature (EIP-1271) or approved hash.
                     * @param requiredSignatures Amount of required valid signatures.
                     */
                    function checkNSignatures(
                        bytes32 dataHash,
                        bytes memory data,
                        bytes memory signatures,
                        uint256 requiredSignatures
                    ) public view {
                        // Check that the provided signature data is not too short
                        require(signatures.length >= requiredSignatures.mul(65), "GS020");
                        // There cannot be an owner with address 0.
                        address lastOwner = address(0);
                        address currentOwner;
                        uint8 v;
                        bytes32 r;
                        bytes32 s;
                        uint256 i;
                        for (i = 0; i < requiredSignatures; i++) {
                            (v, r, s) = signatureSplit(signatures, i);
                            if (v == 0) {
                                // If v is 0 then it is a contract signature
                                // When handling contract signatures the address of the contract is encoded into r
                                currentOwner = address(uint160(uint256(r)));
                                // Check that signature data pointer (s) is not pointing inside the static part of the signatures bytes
                                // This check is not completely accurate, since it is possible that more signatures than the threshold are send.
                                // Here we only check that the pointer is not pointing inside the part that is being processed
                                require(uint256(s) >= requiredSignatures.mul(65), "GS021");
                                // Check that signature data pointer (s) is in bounds (points to the length of data -> 32 bytes)
                                require(uint256(s).add(32) <= signatures.length, "GS022");
                                // Check if the contract signature is in bounds: start of data is s + 32 and end is start + signature length
                                uint256 contractSignatureLen;
                                // solhint-disable-next-line no-inline-assembly
                                assembly {
                                    contractSignatureLen := mload(add(add(signatures, s), 0x20))
                                }
                                require(uint256(s).add(32).add(contractSignatureLen) <= signatures.length, "GS023");
                                // Check signature
                                bytes memory contractSignature;
                                // solhint-disable-next-line no-inline-assembly
                                assembly {
                                    // The signature data for contract signatures is appended to the concatenated signatures and the offset is stored in s
                                    contractSignature := add(add(signatures, s), 0x20)
                                }
                                require(ISignatureValidator(currentOwner).isValidSignature(data, contractSignature) == EIP1271_MAGIC_VALUE, "GS024");
                            } else if (v == 1) {
                                // If v is 1 then it is an approved hash
                                // When handling approved hashes the address of the approver is encoded into r
                                currentOwner = address(uint160(uint256(r)));
                                // Hashes are automatically approved by the sender of the message or when they have been pre-approved via a separate transaction
                                require(msg.sender == currentOwner || approvedHashes[currentOwner][dataHash] != 0, "GS025");
                            } else if (v > 30) {
                                // If v > 30 then default va (27,28) has been adjusted for eth_sign flow
                                // To support eth_sign and similar we adjust v and hash the messageHash with the Ethereum message prefix before applying ecrecover
                                currentOwner = ecrecover(keccak256(abi.encodePacked("\\x19Ethereum Signed Message:\
                32", dataHash)), v - 4, r, s);
                            } else {
                                // Default is the ecrecover flow with the provided data hash
                                // Use ecrecover with the messageHash for EOA signatures
                                currentOwner = ecrecover(dataHash, v, r, s);
                            }
                            require(currentOwner > lastOwner && owners[currentOwner] != address(0) && currentOwner != SENTINEL_OWNERS, "GS026");
                            lastOwner = currentOwner;
                        }
                    }
                    /// @dev Allows to estimate a Safe transaction.
                    ///      This method is only meant for estimation purpose, therefore the call will always revert and encode the result in the revert data.
                    ///      Since the `estimateGas` function includes refunds, call this method to get an estimated of the costs that are deducted from the safe with `execTransaction`
                    /// @param to Destination address of Safe transaction.
                    /// @param value Ether value of Safe transaction.
                    /// @param data Data payload of Safe transaction.
                    /// @param operation Operation type of Safe transaction.
                    /// @return Estimate without refunds and overhead fees (base transaction and payload data gas costs).
                    /// @notice Deprecated in favor of common/StorageAccessible.sol and will be removed in next version.
                    function requiredTxGas(
                        address to,
                        uint256 value,
                        bytes calldata data,
                        Enum.Operation operation
                    ) external returns (uint256) {
                        uint256 startGas = gasleft();
                        // We don't provide an error message here, as we use it to return the estimate
                        require(execute(to, value, data, operation, gasleft()));
                        uint256 requiredGas = startGas - gasleft();
                        // Convert response to string and return via error message
                        revert(string(abi.encodePacked(requiredGas)));
                    }
                    /**
                     * @dev Marks a hash as approved. This can be used to validate a hash that is used by a signature.
                     * @param hashToApprove The hash that should be marked as approved for signatures that are verified by this contract.
                     */
                    function approveHash(bytes32 hashToApprove) external {
                        require(owners[msg.sender] != address(0), "GS030");
                        approvedHashes[msg.sender][hashToApprove] = 1;
                        emit ApproveHash(hashToApprove, msg.sender);
                    }
                    /// @dev Returns the chain id used by this contract.
                    function getChainId() public view returns (uint256) {
                        uint256 id;
                        // solhint-disable-next-line no-inline-assembly
                        assembly {
                            id := chainid()
                        }
                        return id;
                    }
                    function domainSeparator() public view returns (bytes32) {
                        return keccak256(abi.encode(DOMAIN_SEPARATOR_TYPEHASH, getChainId(), this));
                    }
                    /// @dev Returns the bytes that are hashed to be signed by owners.
                    /// @param to Destination address.
                    /// @param value Ether value.
                    /// @param data Data payload.
                    /// @param operation Operation type.
                    /// @param safeTxGas Gas that should be used for the safe transaction.
                    /// @param baseGas Gas costs for that are independent of the transaction execution(e.g. base transaction fee, signature check, payment of the refund)
                    /// @param gasPrice Maximum gas price that should be used for this transaction.
                    /// @param gasToken Token address (or 0 if ETH) that is used for the payment.
                    /// @param refundReceiver Address of receiver of gas payment (or 0 if tx.origin).
                    /// @param _nonce Transaction nonce.
                    /// @return Transaction hash bytes.
                    function encodeTransactionData(
                        address to,
                        uint256 value,
                        bytes calldata data,
                        Enum.Operation operation,
                        uint256 safeTxGas,
                        uint256 baseGas,
                        uint256 gasPrice,
                        address gasToken,
                        address refundReceiver,
                        uint256 _nonce
                    ) public view returns (bytes memory) {
                        bytes32 safeTxHash =
                            keccak256(
                                abi.encode(
                                    SAFE_TX_TYPEHASH,
                                    to,
                                    value,
                                    keccak256(data),
                                    operation,
                                    safeTxGas,
                                    baseGas,
                                    gasPrice,
                                    gasToken,
                                    refundReceiver,
                                    _nonce
                                )
                            );
                        return abi.encodePacked(bytes1(0x19), bytes1(0x01), domainSeparator(), safeTxHash);
                    }
                    /// @dev Returns hash to be signed by owners.
                    /// @param to Destination address.
                    /// @param value Ether value.
                    /// @param data Data payload.
                    /// @param operation Operation type.
                    /// @param safeTxGas Fas that should be used for the safe transaction.
                    /// @param baseGas Gas costs for data used to trigger the safe transaction.
                    /// @param gasPrice Maximum gas price that should be used for this transaction.
                    /// @param gasToken Token address (or 0 if ETH) that is used for the payment.
                    /// @param refundReceiver Address of receiver of gas payment (or 0 if tx.origin).
                    /// @param _nonce Transaction nonce.
                    /// @return Transaction hash.
                    function getTransactionHash(
                        address to,
                        uint256 value,
                        bytes calldata data,
                        Enum.Operation operation,
                        uint256 safeTxGas,
                        uint256 baseGas,
                        uint256 gasPrice,
                        address gasToken,
                        address refundReceiver,
                        uint256 _nonce
                    ) public view returns (bytes32) {
                        return keccak256(encodeTransactionData(to, value, data, operation, safeTxGas, baseGas, gasPrice, gasToken, refundReceiver, _nonce));
                    }
                }
                // SPDX-License-Identifier: LGPL-3.0-only
                pragma solidity >=0.7.0 <0.9.0;
                import "../common/Enum.sol";
                /// @title Executor - A contract that can execute transactions
                /// @author Richard Meissner - <[email protected]>
                contract Executor {
                    function execute(
                        address to,
                        uint256 value,
                        bytes memory data,
                        Enum.Operation operation,
                        uint256 txGas
                    ) internal returns (bool success) {
                        if (operation == Enum.Operation.DelegateCall) {
                            // solhint-disable-next-line no-inline-assembly
                            assembly {
                                success := delegatecall(txGas, to, add(data, 0x20), mload(data), 0, 0)
                            }
                        } else {
                            // solhint-disable-next-line no-inline-assembly
                            assembly {
                                success := call(txGas, to, value, add(data, 0x20), mload(data), 0, 0)
                            }
                        }
                    }
                }
                // SPDX-License-Identifier: LGPL-3.0-only
                pragma solidity >=0.7.0 <0.9.0;
                import "../common/SelfAuthorized.sol";
                /// @title Fallback Manager - A contract that manages fallback calls made to this contract
                /// @author Richard Meissner - <[email protected]>
                contract FallbackManager is SelfAuthorized {
                    event ChangedFallbackHandler(address handler);
                    // keccak256("fallback_manager.handler.address")
                    bytes32 internal constant FALLBACK_HANDLER_STORAGE_SLOT = 0x6c9a6c4a39284e37ed1cf53d337577d14212a4870fb976a4366c693b939918d5;
                    function internalSetFallbackHandler(address handler) internal {
                        bytes32 slot = FALLBACK_HANDLER_STORAGE_SLOT;
                        // solhint-disable-next-line no-inline-assembly
                        assembly {
                            sstore(slot, handler)
                        }
                    }
                    /// @dev Allows to add a contract to handle fallback calls.
                    ///      Only fallback calls without value and with data will be forwarded.
                    ///      This can only be done via a Safe transaction.
                    /// @param handler contract to handle fallbacks calls.
                    function setFallbackHandler(address handler) public authorized {
                        internalSetFallbackHandler(handler);
                        emit ChangedFallbackHandler(handler);
                    }
                    // solhint-disable-next-line payable-fallback,no-complex-fallback
                    fallback() external {
                        bytes32 slot = FALLBACK_HANDLER_STORAGE_SLOT;
                        // solhint-disable-next-line no-inline-assembly
                        assembly {
                            let handler := sload(slot)
                            if iszero(handler) {
                                return(0, 0)
                            }
                            calldatacopy(0, 0, calldatasize())
                            // The msg.sender address is shifted to the left by 12 bytes to remove the padding
                            // Then the address without padding is stored right after the calldata
                            mstore(calldatasize(), shl(96, caller()))
                            // Add 20 bytes for the address appended add the end
                            let success := call(gas(), handler, 0, 0, add(calldatasize(), 20), 0, 0)
                            returndatacopy(0, 0, returndatasize())
                            if iszero(success) {
                                revert(0, returndatasize())
                            }
                            return(0, returndatasize())
                        }
                    }
                }
                // SPDX-License-Identifier: LGPL-3.0-only
                pragma solidity >=0.7.0 <0.9.0;
                import "../common/Enum.sol";
                import "../common/SelfAuthorized.sol";
                interface Guard {
                    function checkTransaction(
                        address to,
                        uint256 value,
                        bytes memory data,
                        Enum.Operation operation,
                        uint256 safeTxGas,
                        uint256 baseGas,
                        uint256 gasPrice,
                        address gasToken,
                        address payable refundReceiver,
                        bytes memory signatures,
                        address msgSender
                    ) external;
                    function checkAfterExecution(bytes32 txHash, bool success) external;
                }
                /// @title Fallback Manager - A contract that manages fallback calls made to this contract
                /// @author Richard Meissner - <[email protected]>
                contract GuardManager is SelfAuthorized {
                    event ChangedGuard(address guard);
                    // keccak256("guard_manager.guard.address")
                    bytes32 internal constant GUARD_STORAGE_SLOT = 0x4a204f620c8c5ccdca3fd54d003badd85ba500436a431f0cbda4f558c93c34c8;
                    /// @dev Set a guard that checks transactions before execution
                    /// @param guard The address of the guard to be used or the 0 address to disable the guard
                    function setGuard(address guard) external authorized {
                        bytes32 slot = GUARD_STORAGE_SLOT;
                        // solhint-disable-next-line no-inline-assembly
                        assembly {
                            sstore(slot, guard)
                        }
                        emit ChangedGuard(guard);
                    }
                    function getGuard() internal view returns (address guard) {
                        bytes32 slot = GUARD_STORAGE_SLOT;
                        // solhint-disable-next-line no-inline-assembly
                        assembly {
                            guard := sload(slot)
                        }
                    }
                }
                // SPDX-License-Identifier: LGPL-3.0-only
                pragma solidity >=0.7.0 <0.9.0;
                import "../common/Enum.sol";
                import "../common/SelfAuthorized.sol";
                import "./Executor.sol";
                /// @title Module Manager - A contract that manages modules that can execute transactions via this contract
                /// @author Stefan George - <[email protected]>
                /// @author Richard Meissner - <[email protected]>
                contract ModuleManager is SelfAuthorized, Executor {
                    event EnabledModule(address module);
                    event DisabledModule(address module);
                    event ExecutionFromModuleSuccess(address indexed module);
                    event ExecutionFromModuleFailure(address indexed module);
                    address internal constant SENTINEL_MODULES = address(0x1);
                    mapping(address => address) internal modules;
                    function setupModules(address to, bytes memory data) internal {
                        require(modules[SENTINEL_MODULES] == address(0), "GS100");
                        modules[SENTINEL_MODULES] = SENTINEL_MODULES;
                        if (to != address(0))
                            // Setup has to complete successfully or transaction fails.
                            require(execute(to, 0, data, Enum.Operation.DelegateCall, gasleft()), "GS000");
                    }
                    /// @dev Allows to add a module to the whitelist.
                    ///      This can only be done via a Safe transaction.
                    /// @notice Enables the module `module` for the Safe.
                    /// @param module Module to be whitelisted.
                    function enableModule(address module) public authorized {
                        // Module address cannot be null or sentinel.
                        require(module != address(0) && module != SENTINEL_MODULES, "GS101");
                        // Module cannot be added twice.
                        require(modules[module] == address(0), "GS102");
                        modules[module] = modules[SENTINEL_MODULES];
                        modules[SENTINEL_MODULES] = module;
                        emit EnabledModule(module);
                    }
                    /// @dev Allows to remove a module from the whitelist.
                    ///      This can only be done via a Safe transaction.
                    /// @notice Disables the module `module` for the Safe.
                    /// @param prevModule Module that pointed to the module to be removed in the linked list
                    /// @param module Module to be removed.
                    function disableModule(address prevModule, address module) public authorized {
                        // Validate module address and check that it corresponds to module index.
                        require(module != address(0) && module != SENTINEL_MODULES, "GS101");
                        require(modules[prevModule] == module, "GS103");
                        modules[prevModule] = modules[module];
                        modules[module] = address(0);
                        emit DisabledModule(module);
                    }
                    /// @dev Allows a Module to execute a Safe transaction without any further confirmations.
                    /// @param to Destination address of module transaction.
                    /// @param value Ether value of module transaction.
                    /// @param data Data payload of module transaction.
                    /// @param operation Operation type of module transaction.
                    function execTransactionFromModule(
                        address to,
                        uint256 value,
                        bytes memory data,
                        Enum.Operation operation
                    ) public virtual returns (bool success) {
                        // Only whitelisted modules are allowed.
                        require(msg.sender != SENTINEL_MODULES && modules[msg.sender] != address(0), "GS104");
                        // Execute transaction without further confirmations.
                        success = execute(to, value, data, operation, gasleft());
                        if (success) emit ExecutionFromModuleSuccess(msg.sender);
                        else emit ExecutionFromModuleFailure(msg.sender);
                    }
                    /// @dev Allows a Module to execute a Safe transaction without any further confirmations and return data
                    /// @param to Destination address of module transaction.
                    /// @param value Ether value of module transaction.
                    /// @param data Data payload of module transaction.
                    /// @param operation Operation type of module transaction.
                    function execTransactionFromModuleReturnData(
                        address to,
                        uint256 value,
                        bytes memory data,
                        Enum.Operation operation
                    ) public returns (bool success, bytes memory returnData) {
                        success = execTransactionFromModule(to, value, data, operation);
                        // solhint-disable-next-line no-inline-assembly
                        assembly {
                            // Load free memory location
                            let ptr := mload(0x40)
                            // We allocate memory for the return data by setting the free memory location to
                            // current free memory location + data size + 32 bytes for data size value
                            mstore(0x40, add(ptr, add(returndatasize(), 0x20)))
                            // Store the size
                            mstore(ptr, returndatasize())
                            // Store the data
                            returndatacopy(add(ptr, 0x20), 0, returndatasize())
                            // Point the return data to the correct memory location
                            returnData := ptr
                        }
                    }
                    /// @dev Returns if an module is enabled
                    /// @return True if the module is enabled
                    function isModuleEnabled(address module) public view returns (bool) {
                        return SENTINEL_MODULES != module && modules[module] != address(0);
                    }
                    /// @dev Returns array of modules.
                    /// @param start Start of the page.
                    /// @param pageSize Maximum number of modules that should be returned.
                    /// @return array Array of modules.
                    /// @return next Start of the next page.
                    function getModulesPaginated(address start, uint256 pageSize) external view returns (address[] memory array, address next) {
                        // Init array with max page size
                        array = new address[](pageSize);
                        // Populate return array
                        uint256 moduleCount = 0;
                        address currentModule = modules[start];
                        while (currentModule != address(0x0) && currentModule != SENTINEL_MODULES && moduleCount < pageSize) {
                            array[moduleCount] = currentModule;
                            currentModule = modules[currentModule];
                            moduleCount++;
                        }
                        next = currentModule;
                        // Set correct size of returned array
                        // solhint-disable-next-line no-inline-assembly
                        assembly {
                            mstore(array, moduleCount)
                        }
                    }
                }
                // SPDX-License-Identifier: LGPL-3.0-only
                pragma solidity >=0.7.0 <0.9.0;
                import "../common/SelfAuthorized.sol";
                /// @title OwnerManager - Manages a set of owners and a threshold to perform actions.
                /// @author Stefan George - <[email protected]>
                /// @author Richard Meissner - <[email protected]>
                contract OwnerManager is SelfAuthorized {
                    event AddedOwner(address owner);
                    event RemovedOwner(address owner);
                    event ChangedThreshold(uint256 threshold);
                    address internal constant SENTINEL_OWNERS = address(0x1);
                    mapping(address => address) internal owners;
                    uint256 internal ownerCount;
                    uint256 internal threshold;
                    /// @dev Setup function sets initial storage of contract.
                    /// @param _owners List of Safe owners.
                    /// @param _threshold Number of required confirmations for a Safe transaction.
                    function setupOwners(address[] memory _owners, uint256 _threshold) internal {
                        // Threshold can only be 0 at initialization.
                        // Check ensures that setup function can only be called once.
                        require(threshold == 0, "GS200");
                        // Validate that threshold is smaller than number of added owners.
                        require(_threshold <= _owners.length, "GS201");
                        // There has to be at least one Safe owner.
                        require(_threshold >= 1, "GS202");
                        // Initializing Safe owners.
                        address currentOwner = SENTINEL_OWNERS;
                        for (uint256 i = 0; i < _owners.length; i++) {
                            // Owner address cannot be null.
                            address owner = _owners[i];
                            require(owner != address(0) && owner != SENTINEL_OWNERS && owner != address(this) && currentOwner != owner, "GS203");
                            // No duplicate owners allowed.
                            require(owners[owner] == address(0), "GS204");
                            owners[currentOwner] = owner;
                            currentOwner = owner;
                        }
                        owners[currentOwner] = SENTINEL_OWNERS;
                        ownerCount = _owners.length;
                        threshold = _threshold;
                    }
                    /// @dev Allows to add a new owner to the Safe and update the threshold at the same time.
                    ///      This can only be done via a Safe transaction.
                    /// @notice Adds the owner `owner` to the Safe and updates the threshold to `_threshold`.
                    /// @param owner New owner address.
                    /// @param _threshold New threshold.
                    function addOwnerWithThreshold(address owner, uint256 _threshold) public authorized {
                        // Owner address cannot be null, the sentinel or the Safe itself.
                        require(owner != address(0) && owner != SENTINEL_OWNERS && owner != address(this), "GS203");
                        // No duplicate owners allowed.
                        require(owners[owner] == address(0), "GS204");
                        owners[owner] = owners[SENTINEL_OWNERS];
                        owners[SENTINEL_OWNERS] = owner;
                        ownerCount++;
                        emit AddedOwner(owner);
                        // Change threshold if threshold was changed.
                        if (threshold != _threshold) changeThreshold(_threshold);
                    }
                    /// @dev Allows to remove an owner from the Safe and update the threshold at the same time.
                    ///      This can only be done via a Safe transaction.
                    /// @notice Removes the owner `owner` from the Safe and updates the threshold to `_threshold`.
                    /// @param prevOwner Owner that pointed to the owner to be removed in the linked list
                    /// @param owner Owner address to be removed.
                    /// @param _threshold New threshold.
                    function removeOwner(
                        address prevOwner,
                        address owner,
                        uint256 _threshold
                    ) public authorized {
                        // Only allow to remove an owner, if threshold can still be reached.
                        require(ownerCount - 1 >= _threshold, "GS201");
                        // Validate owner address and check that it corresponds to owner index.
                        require(owner != address(0) && owner != SENTINEL_OWNERS, "GS203");
                        require(owners[prevOwner] == owner, "GS205");
                        owners[prevOwner] = owners[owner];
                        owners[owner] = address(0);
                        ownerCount--;
                        emit RemovedOwner(owner);
                        // Change threshold if threshold was changed.
                        if (threshold != _threshold) changeThreshold(_threshold);
                    }
                    /// @dev Allows to swap/replace an owner from the Safe with another address.
                    ///      This can only be done via a Safe transaction.
                    /// @notice Replaces the owner `oldOwner` in the Safe with `newOwner`.
                    /// @param prevOwner Owner that pointed to the owner to be replaced in the linked list
                    /// @param oldOwner Owner address to be replaced.
                    /// @param newOwner New owner address.
                    function swapOwner(
                        address prevOwner,
                        address oldOwner,
                        address newOwner
                    ) public authorized {
                        // Owner address cannot be null, the sentinel or the Safe itself.
                        require(newOwner != address(0) && newOwner != SENTINEL_OWNERS && newOwner != address(this), "GS203");
                        // No duplicate owners allowed.
                        require(owners[newOwner] == address(0), "GS204");
                        // Validate oldOwner address and check that it corresponds to owner index.
                        require(oldOwner != address(0) && oldOwner != SENTINEL_OWNERS, "GS203");
                        require(owners[prevOwner] == oldOwner, "GS205");
                        owners[newOwner] = owners[oldOwner];
                        owners[prevOwner] = newOwner;
                        owners[oldOwner] = address(0);
                        emit RemovedOwner(oldOwner);
                        emit AddedOwner(newOwner);
                    }
                    /// @dev Allows to update the number of required confirmations by Safe owners.
                    ///      This can only be done via a Safe transaction.
                    /// @notice Changes the threshold of the Safe to `_threshold`.
                    /// @param _threshold New threshold.
                    function changeThreshold(uint256 _threshold) public authorized {
                        // Validate that threshold is smaller than number of owners.
                        require(_threshold <= ownerCount, "GS201");
                        // There has to be at least one Safe owner.
                        require(_threshold >= 1, "GS202");
                        threshold = _threshold;
                        emit ChangedThreshold(threshold);
                    }
                    function getThreshold() public view returns (uint256) {
                        return threshold;
                    }
                    function isOwner(address owner) public view returns (bool) {
                        return owner != SENTINEL_OWNERS && owners[owner] != address(0);
                    }
                    /// @dev Returns array of owners.
                    /// @return Array of Safe owners.
                    function getOwners() public view returns (address[] memory) {
                        address[] memory array = new address[](ownerCount);
                        // populate return array
                        uint256 index = 0;
                        address currentOwner = owners[SENTINEL_OWNERS];
                        while (currentOwner != SENTINEL_OWNERS) {
                            array[index] = currentOwner;
                            currentOwner = owners[currentOwner];
                            index++;
                        }
                        return array;
                    }
                }
                // SPDX-License-Identifier: LGPL-3.0-only
                pragma solidity >=0.7.0 <0.9.0;
                /// @title Enum - Collection of enums
                /// @author Richard Meissner - <[email protected]>
                contract Enum {
                    enum Operation {Call, DelegateCall}
                }
                // SPDX-License-Identifier: LGPL-3.0-only
                pragma solidity >=0.7.0 <0.9.0;
                /// @title EtherPaymentFallback - A contract that has a fallback to accept ether payments
                /// @author Richard Meissner - <[email protected]>
                contract EtherPaymentFallback {
                    event SafeReceived(address indexed sender, uint256 value);
                    /// @dev Fallback function accepts Ether transactions.
                    receive() external payable {
                        emit SafeReceived(msg.sender, msg.value);
                    }
                }
                // SPDX-License-Identifier: LGPL-3.0-only
                pragma solidity >=0.7.0 <0.9.0;
                /// @title SecuredTokenTransfer - Secure token transfer
                /// @author Richard Meissner - <[email protected]>
                contract SecuredTokenTransfer {
                    /// @dev Transfers a token and returns if it was a success
                    /// @param token Token that should be transferred
                    /// @param receiver Receiver to whom the token should be transferred
                    /// @param amount The amount of tokens that should be transferred
                    function transferToken(
                        address token,
                        address receiver,
                        uint256 amount
                    ) internal returns (bool transferred) {
                        // 0xa9059cbb - keccack("transfer(address,uint256)")
                        bytes memory data = abi.encodeWithSelector(0xa9059cbb, receiver, amount);
                        // solhint-disable-next-line no-inline-assembly
                        assembly {
                            // We write the return value to scratch space.
                            // See https://docs.soliditylang.org/en/v0.7.6/internals/layout_in_memory.html#layout-in-memory
                            let success := call(sub(gas(), 10000), token, 0, add(data, 0x20), mload(data), 0, 0x20)
                            switch returndatasize()
                                case 0 {
                                    transferred := success
                                }
                                case 0x20 {
                                    transferred := iszero(or(iszero(success), iszero(mload(0))))
                                }
                                default {
                                    transferred := 0
                                }
                        }
                    }
                }
                // SPDX-License-Identifier: LGPL-3.0-only
                pragma solidity >=0.7.0 <0.9.0;
                /// @title SelfAuthorized - authorizes current contract to perform actions
                /// @author Richard Meissner - <[email protected]>
                contract SelfAuthorized {
                    function requireSelfCall() private view {
                        require(msg.sender == address(this), "GS031");
                    }
                    modifier authorized() {
                        // This is a function call as it minimized the bytecode size
                        requireSelfCall();
                        _;
                    }
                }
                // SPDX-License-Identifier: LGPL-3.0-only
                pragma solidity >=0.7.0 <0.9.0;
                /// @title SignatureDecoder - Decodes signatures that a encoded as bytes
                /// @author Richard Meissner - <[email protected]>
                contract SignatureDecoder {
                    /// @dev divides bytes signature into `uint8 v, bytes32 r, bytes32 s`.
                    /// @notice Make sure to peform a bounds check for @param pos, to avoid out of bounds access on @param signatures
                    /// @param pos which signature to read. A prior bounds check of this parameter should be performed, to avoid out of bounds access
                    /// @param signatures concatenated rsv signatures
                    function signatureSplit(bytes memory signatures, uint256 pos)
                        internal
                        pure
                        returns (
                            uint8 v,
                            bytes32 r,
                            bytes32 s
                        )
                    {
                        // The signature format is a compact form of:
                        //   {bytes32 r}{bytes32 s}{uint8 v}
                        // Compact means, uint8 is not padded to 32 bytes.
                        // solhint-disable-next-line no-inline-assembly
                        assembly {
                            let signaturePos := mul(0x41, pos)
                            r := mload(add(signatures, add(signaturePos, 0x20)))
                            s := mload(add(signatures, add(signaturePos, 0x40)))
                            // Here we are loading the last 32 bytes, including 31 bytes
                            // of 's'. There is no 'mload8' to do this.
                            //
                            // 'byte' is not working due to the Solidity parser, so lets
                            // use the second best option, 'and'
                            v := and(mload(add(signatures, add(signaturePos, 0x41))), 0xff)
                        }
                    }
                }
                // SPDX-License-Identifier: LGPL-3.0-only
                pragma solidity >=0.7.0 <0.9.0;
                /// @title Singleton - Base for singleton contracts (should always be first super contract)
                ///         This contract is tightly coupled to our proxy contract (see `proxies/GnosisSafeProxy.sol`)
                /// @author Richard Meissner - <[email protected]>
                contract Singleton {
                    // singleton always needs to be first declared variable, to ensure that it is at the same location as in the Proxy contract.
                    // It should also always be ensured that the address is stored alone (uses a full word)
                    address private singleton;
                }
                // SPDX-License-Identifier: LGPL-3.0-only
                pragma solidity >=0.7.0 <0.9.0;
                /// @title StorageAccessible - generic base contract that allows callers to access all internal storage.
                /// @notice See https://github.com/gnosis/util-contracts/blob/bb5fe5fb5df6d8400998094fb1b32a178a47c3a1/contracts/StorageAccessible.sol
                contract StorageAccessible {
                    /**
                     * @dev Reads `length` bytes of storage in the currents contract
                     * @param offset - the offset in the current contract's storage in words to start reading from
                     * @param length - the number of words (32 bytes) of data to read
                     * @return the bytes that were read.
                     */
                    function getStorageAt(uint256 offset, uint256 length) public view returns (bytes memory) {
                        bytes memory result = new bytes(length * 32);
                        for (uint256 index = 0; index < length; index++) {
                            // solhint-disable-next-line no-inline-assembly
                            assembly {
                                let word := sload(add(offset, index))
                                mstore(add(add(result, 0x20), mul(index, 0x20)), word)
                            }
                        }
                        return result;
                    }
                    /**
                     * @dev Performs a delegetecall on a targetContract in the context of self.
                     * Internally reverts execution to avoid side effects (making it static).
                     *
                     * This method reverts with data equal to `abi.encode(bool(success), bytes(response))`.
                     * Specifically, the `returndata` after a call to this method will be:
                     * `success:bool || response.length:uint256 || response:bytes`.
                     *
                     * @param targetContract Address of the contract containing the code to execute.
                     * @param calldataPayload Calldata that should be sent to the target contract (encoded method name and arguments).
                     */
                    function simulateAndRevert(address targetContract, bytes memory calldataPayload) external {
                        // solhint-disable-next-line no-inline-assembly
                        assembly {
                            let success := delegatecall(gas(), targetContract, add(calldataPayload, 0x20), mload(calldataPayload), 0, 0)
                            mstore(0x00, success)
                            mstore(0x20, returndatasize())
                            returndatacopy(0x40, 0, returndatasize())
                            revert(0, add(returndatasize(), 0x40))
                        }
                    }
                }
                // SPDX-License-Identifier: LGPL-3.0-only
                pragma solidity >=0.7.0 <0.9.0;
                /**
                 * @title GnosisSafeMath
                 * @dev Math operations with safety checks that revert on error
                 * Renamed from SafeMath to GnosisSafeMath to avoid conflicts
                 * TODO: remove once open zeppelin update to solc 0.5.0
                 */
                library GnosisSafeMath {
                    /**
                     * @dev Multiplies two numbers, reverts on 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);
                        return c;
                    }
                    /**
                     * @dev Subtracts two numbers, reverts on overflow (i.e. if subtrahend is greater than minuend).
                     */
                    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
                        require(b <= a);
                        uint256 c = a - b;
                        return c;
                    }
                    /**
                     * @dev Adds two numbers, reverts on overflow.
                     */
                    function add(uint256 a, uint256 b) internal pure returns (uint256) {
                        uint256 c = a + b;
                        require(c >= a);
                        return c;
                    }
                    /**
                     * @dev Returns the largest of two numbers.
                     */
                    function max(uint256 a, uint256 b) internal pure returns (uint256) {
                        return a >= b ? a : b;
                    }
                }
                // SPDX-License-Identifier: LGPL-3.0-only
                pragma solidity >=0.7.0 <0.9.0;
                contract ISignatureValidatorConstants {
                    // bytes4(keccak256("isValidSignature(bytes,bytes)")
                    bytes4 internal constant EIP1271_MAGIC_VALUE = 0x20c13b0b;
                }
                abstract contract ISignatureValidator is ISignatureValidatorConstants {
                    /**
                     * @dev Should return whether the signature provided is valid for the provided data
                     * @param _data Arbitrary length data signed on the behalf of address(this)
                     * @param _signature Signature byte array associated with _data
                     *
                     * MUST return the bytes4 magic value 0x20c13b0b when function passes.
                     * MUST NOT modify state (using STATICCALL for solc < 0.5, view modifier for solc > 0.5)
                     * MUST allow external calls
                     */
                    function isValidSignature(bytes memory _data, bytes memory _signature) public view virtual returns (bytes4);
                }
                

                File 4 of 4: MultiSendCallOnly
                // SPDX-License-Identifier: LGPL-3.0-only
                pragma solidity >=0.7.0 <0.9.0;
                /// @title Multi Send Call Only - Allows to batch multiple transactions into one, but only calls
                /// @author Stefan George - <[email protected]>
                /// @author Richard Meissner - <[email protected]>
                /// @notice The guard logic is not required here as this contract doesn't support nested delegate calls
                contract MultiSendCallOnly {
                    /// @dev Sends multiple transactions and reverts all if one fails.
                    /// @param transactions Encoded transactions. Each transaction is encoded as a packed bytes of
                    ///                     operation has to be uint8(0) in this version (=> 1 byte),
                    ///                     to as a address (=> 20 bytes),
                    ///                     value as a uint256 (=> 32 bytes),
                    ///                     data length as a uint256 (=> 32 bytes),
                    ///                     data as bytes.
                    ///                     see abi.encodePacked for more information on packed encoding
                    /// @notice The code is for most part the same as the normal MultiSend (to keep compatibility),
                    ///         but reverts if a transaction tries to use a delegatecall.
                    /// @notice This method is payable as delegatecalls keep the msg.value from the previous call
                    ///         If the calling method (e.g. execTransaction) received ETH this would revert otherwise
                    function multiSend(bytes memory transactions) public payable {
                        // solhint-disable-next-line no-inline-assembly
                        assembly {
                            let length := mload(transactions)
                            let i := 0x20
                            for {
                                // Pre block is not used in "while mode"
                            } lt(i, length) {
                                // Post block is not used in "while mode"
                            } {
                                // First byte of the data is the operation.
                                // We shift by 248 bits (256 - 8 [operation byte]) it right since mload will always load 32 bytes (a word).
                                // This will also zero out unused data.
                                let operation := shr(0xf8, mload(add(transactions, i)))
                                // We offset the load address by 1 byte (operation byte)
                                // We shift it right by 96 bits (256 - 160 [20 address bytes]) to right-align the data and zero out unused data.
                                let to := shr(0x60, mload(add(transactions, add(i, 0x01))))
                                // We offset the load address by 21 byte (operation byte + 20 address bytes)
                                let value := mload(add(transactions, add(i, 0x15)))
                                // We offset the load address by 53 byte (operation byte + 20 address bytes + 32 value bytes)
                                let dataLength := mload(add(transactions, add(i, 0x35)))
                                // We offset the load address by 85 byte (operation byte + 20 address bytes + 32 value bytes + 32 data length bytes)
                                let data := add(transactions, add(i, 0x55))
                                let success := 0
                                switch operation
                                    case 0 {
                                        success := call(gas(), to, value, data, dataLength, 0, 0)
                                    }
                                    // This version does not allow delegatecalls
                                    case 1 {
                                        revert(0, 0)
                                    }
                                if eq(success, 0) {
                                    revert(0, 0)
                                }
                                // Next entry starts at 85 byte + data length
                                i := add(i, add(0x55, dataLength))
                            }
                        }
                    }
                }