ETH Price: $2,761.47 (+4.35%)

Transaction Decoder

Block:
15035013 at Jun-27-2022 03:17:18 PM +UTC
Transaction Fee:
0.039590886755364215 ETH $109.33
Gas Used:
616,235 Gas / 64.246410469 Gwei

Emitted Events:

480 0x2ca7641b841a79cc70220ce838d0b9f8197accda.0x44c58d81365b66dd4b1a7f36c25aa97b8c71c361ee4937adc1a00000227db5dd( 0x44c58d81365b66dd4b1a7f36c25aa97b8c71c361ee4937adc1a00000227db5dd, 0x000000000000000000000000c2c3ae0a7b405058558c9b4a63b373486cb86ac7, 0x000000000000000000000000e0e3d9e170ca8375b96bdda0b87e56958b046999 )
481 0x075da7e9efea6813ab0b2680423df75150120d12.0x4beccb90f994c31aced7a23b5611020728a23d8ec5cddd1a3e9d97b96fda8666( 0x4beccb90f994c31aced7a23b5611020728a23d8ec5cddd1a3e9d97b96fda8666, 0x000000000000000000000000e0e3d9e170ca8375b96bdda0b87e56958b046999, 0x0000000000000000000000003ee18b2214aff97000d974cf647e7c347e8fa585, 00000000000000000000000000000000000000000000000000000004a817c800, 0000000000000000000000000000000000000000033b2e3c9fd0803ce8000000 )
482 0x075da7e9efea6813ab0b2680423df75150120d12.0x8c5be1e5ebec7d5bd14f71427d1e84f3dd0314c0f7b2291e5b200ac8c7c3b925( 0x8c5be1e5ebec7d5bd14f71427d1e84f3dd0314c0f7b2291e5b200ac8c7c3b925, 0x000000000000000000000000e0e3d9e170ca8375b96bdda0b87e56958b046999, 0x0000000000000000000000003ee18b2214aff97000d974cf647e7c347e8fa585, fffffffffffffffffffffffffffffffffffffffffffffffffffffffb57e837ff )
483 0x075da7e9efea6813ab0b2680423df75150120d12.0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef( 0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef, 0x000000000000000000000000e0e3d9e170ca8375b96bdda0b87e56958b046999, 0x0000000000000000000000003ee18b2214aff97000d974cf647e7c347e8fa585, 00000000000000000000000000000000000000000000000000000004a817c800 )
484 Wormhole.0x6eb224fb001ed210e379b335e35efe88672a8ce935d981a6896b27ffdf52a3b2( 0x6eb224fb001ed210e379b335e35efe88672a8ce935d981a6896b27ffdf52a3b2, 0x0000000000000000000000003ee18b2214aff97000d974cf647e7c347e8fa585, 000000000000000000000000000000000000000000000000000000000001190b, 00000000000000000000000000000000000000000000000000000000d6ec0000, 0000000000000000000000000000000000000000000000000000000000000080, 000000000000000000000000000000000000000000000000000000000000000f, 0000000000000000000000000000000000000000000000000000000000000085, 0100000000000000000000000000000000000000000000000000000004a817c8, 00000000000000000000000000075da7e9efea6813ab0b2680423df75150120d, 120002000000000000000000000000e0e3d9e170ca8375b96bdda0b87e56958b, 0469990005000000000000000000000000000000000000000000000000000000, 0000000000000000000000000000000000000000000000000000000000000000 )

Account State Difference:

  Address   Before After State Difference Code
0x075dA7e9...150120d12
0x2Ca7641B...8197accDA
0x3ee18B22...47E8fa585
(Wormhole: Token Bridge)
0x98f3c9e6...f1464288B
(Wormhole: Ethereum Core Bridge)
0xe0e3d9e1...58B046999
1.489302958554722602 Eth
Nonce: 423
1.449712071799358387 Eth
Nonce: 424
0.039590886755364215
(Ethermine)
2,989.378328472093371517 Eth2,989.379252824593371517 Eth0.0009243525

Execution Trace

TokenBridge.0f5287b0( )
  • BridgeImplementation.transferTokens( token=0x075dA7e9EFEA6813aB0B2680423df75150120d12, amount=20000000000, recipientChain=5, recipient=000000000000000000000000E0E3D9E170CA8375B96BDDA0B87E56958B046999, arbiterFee=0, nonce=3605790720 ) => ( sequence=71947 )
    • 0x075da7e9efea6813ab0b2680423df75150120d12.STATICCALL( )
      • 0x1cf0d5ab75d82dc6b8afc6d37d0cd8af4c6beff6.DELEGATECALL( )
      • 0x075da7e9efea6813ab0b2680423df75150120d12.70a08231( )
        • 0x1cf0d5ab75d82dc6b8afc6d37d0cd8af4c6beff6.70a08231( )
          • 0x2ca7641b841a79cc70220ce838d0b9f8197accda.d15e0053( )
            • 0x0d10520a3ec2f26cd843a7b8ebf85e6c74c4a8e8.d15e0053( )
            • 0x075da7e9efea6813ab0b2680423df75150120d12.23b872dd( )
              • 0x1cf0d5ab75d82dc6b8afc6d37d0cd8af4c6beff6.23b872dd( )
                • 0x2ca7641b841a79cc70220ce838d0b9f8197accda.d15e0053( )
                  • 0x0d10520a3ec2f26cd843a7b8ebf85e6c74c4a8e8.d15e0053( )
                  • 0x2ca7641b841a79cc70220ce838d0b9f8197accda.d5ed3933( )
                    • 0x0d10520a3ec2f26cd843a7b8ebf85e6c74c4a8e8.d5ed3933( )
                      • 0x1f96045fb8e9302d7dec37a87f4b746442cdd675.STATICCALL( )
                      • 0x5d06008f058a86e58d5133c843bca535fc1bf270.b3596f07( )
                      • 0x075da7e9efea6813ab0b2680423df75150120d12.70a08231( )
                      • 0x075da7e9efea6813ab0b2680423df75150120d12.70a08231( )
                        • 0x1cf0d5ab75d82dc6b8afc6d37d0cd8af4c6beff6.70a08231( )
                          • 0x2ca7641b841a79cc70220ce838d0b9f8197accda.d15e0053( )
                            • 0x0d10520a3ec2f26cd843a7b8ebf85e6c74c4a8e8.d15e0053( )
                            • Wormhole.b19a437e( )
                              • Implementation.publishMessage( nonce=3605790720, payload=0x0100000000000000000000000000000000000000000000000000000004A817C800000000000000000000000000075DA7E9EFEA6813AB0B2680423DF75150120D120002000000000000000000000000E0E3D9E170CA8375B96BDDA0B87E56958B04699900050000000000000000000000000000000000000000000000000000000000000000, consistencyLevel=15 ) => ( sequence=71947 )
                                File 1 of 4: TokenBridge
                                // contracts/Wormhole.sol
                                // SPDX-License-Identifier: Apache 2
                                pragma solidity ^0.8.0;
                                import "@openzeppelin/contracts/proxy/ERC1967/ERC1967Proxy.sol";
                                contract TokenBridge is ERC1967Proxy {
                                    constructor (address implementation, bytes memory initData)
                                    ERC1967Proxy(
                                        implementation,
                                        initData
                                    )
                                    {}
                                }// SPDX-License-Identifier: MIT
                                pragma solidity ^0.8.0;
                                import "../Proxy.sol";
                                import "./ERC1967Upgrade.sol";
                                /**
                                 * @dev This contract implements an upgradeable proxy. It is upgradeable because calls are delegated to an
                                 * implementation address that can be changed. This address is stored in storage in the location specified by
                                 * https://eips.ethereum.org/EIPS/eip-1967[EIP1967], so that it doesn't conflict with the storage layout of the
                                 * implementation behind the proxy.
                                 */
                                contract ERC1967Proxy is Proxy, ERC1967Upgrade {
                                    /**
                                     * @dev Initializes the upgradeable proxy with an initial implementation specified by `_logic`.
                                     *
                                     * If `_data` is nonempty, it's used as data in a delegate call to `_logic`. This will typically be an encoded
                                     * function call, and allows initializating the storage of the proxy like a Solidity constructor.
                                     */
                                    constructor(address _logic, bytes memory _data) payable {
                                        assert(_IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1));
                                        _upgradeToAndCall(_logic, _data, false);
                                    }
                                    /**
                                     * @dev Returns the current implementation address.
                                     */
                                    function _implementation() internal view virtual override returns (address impl) {
                                        return ERC1967Upgrade._getImplementation();
                                    }
                                }
                                // SPDX-License-Identifier: MIT
                                pragma solidity ^0.8.2;
                                import "../beacon/IBeacon.sol";
                                import "../../utils/Address.sol";
                                import "../../utils/StorageSlot.sol";
                                /**
                                 * @dev This abstract contract provides getters and event emitting update functions for
                                 * https://eips.ethereum.org/EIPS/eip-1967[EIP1967] slots.
                                 *
                                 * _Available since v4.1._
                                 *
                                 * @custom:oz-upgrades-unsafe-allow delegatecall
                                 */
                                abstract contract ERC1967Upgrade {
                                    // This is the keccak-256 hash of "eip1967.proxy.rollback" subtracted by 1
                                    bytes32 private constant _ROLLBACK_SLOT = 0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;
                                    /**
                                     * @dev Storage slot with the address of the current implementation.
                                     * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
                                     * validated in the constructor.
                                     */
                                    bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
                                    /**
                                     * @dev Emitted when the implementation is upgraded.
                                     */
                                    event Upgraded(address indexed implementation);
                                    /**
                                     * @dev Returns the current implementation address.
                                     */
                                    function _getImplementation() internal view returns (address) {
                                        return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
                                    }
                                    /**
                                     * @dev Stores a new address in the EIP1967 implementation slot.
                                     */
                                    function _setImplementation(address newImplementation) private {
                                        require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
                                        StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
                                    }
                                    /**
                                     * @dev Perform implementation upgrade
                                     *
                                     * Emits an {Upgraded} event.
                                     */
                                    function _upgradeTo(address newImplementation) internal {
                                        _setImplementation(newImplementation);
                                        emit Upgraded(newImplementation);
                                    }
                                    /**
                                     * @dev Perform implementation upgrade with additional setup call.
                                     *
                                     * Emits an {Upgraded} event.
                                     */
                                    function _upgradeToAndCall(address newImplementation, bytes memory data, bool forceCall) internal {
                                        _setImplementation(newImplementation);
                                        emit Upgraded(newImplementation);
                                        if (data.length > 0 || forceCall) {
                                            Address.functionDelegateCall(newImplementation, data);
                                        }
                                    }
                                    /**
                                     * @dev Perform implementation upgrade with security checks for UUPS proxies, and additional setup call.
                                     *
                                     * Emits an {Upgraded} event.
                                     */
                                    function _upgradeToAndCallSecure(address newImplementation, bytes memory data, bool forceCall) internal {
                                        address oldImplementation = _getImplementation();
                                        // Initial upgrade and setup call
                                        _setImplementation(newImplementation);
                                        if (data.length > 0 || forceCall) {
                                            Address.functionDelegateCall(newImplementation, data);
                                        }
                                        // Perform rollback test if not already in progress
                                        StorageSlot.BooleanSlot storage rollbackTesting = StorageSlot.getBooleanSlot(_ROLLBACK_SLOT);
                                        if (!rollbackTesting.value) {
                                            // Trigger rollback using upgradeTo from the new implementation
                                            rollbackTesting.value = true;
                                            Address.functionDelegateCall(
                                                newImplementation,
                                                abi.encodeWithSignature(
                                                    "upgradeTo(address)",
                                                    oldImplementation
                                                )
                                            );
                                            rollbackTesting.value = false;
                                            // Check rollback was effective
                                            require(oldImplementation == _getImplementation(), "ERC1967Upgrade: upgrade breaks further upgrades");
                                            // Finally reset to the new implementation and log the upgrade
                                            _setImplementation(newImplementation);
                                            emit Upgraded(newImplementation);
                                        }
                                    }
                                    /**
                                     * @dev Perform beacon upgrade with additional setup call. Note: This upgrades the address of the beacon, it does
                                     * not upgrade the implementation contained in the beacon (see {UpgradeableBeacon-_setImplementation} for that).
                                     *
                                     * Emits a {BeaconUpgraded} event.
                                     */
                                    function _upgradeBeaconToAndCall(address newBeacon, bytes memory data, bool forceCall) internal {
                                        _setBeacon(newBeacon);
                                        emit BeaconUpgraded(newBeacon);
                                        if (data.length > 0 || forceCall) {
                                            Address.functionDelegateCall(IBeacon(newBeacon).implementation(), data);
                                        }
                                    }
                                    /**
                                     * @dev Storage slot with the admin of the contract.
                                     * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
                                     * validated in the constructor.
                                     */
                                    bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
                                    /**
                                     * @dev Emitted when the admin account has changed.
                                     */
                                    event AdminChanged(address previousAdmin, address newAdmin);
                                    /**
                                     * @dev Returns the current admin.
                                     */
                                    function _getAdmin() internal view returns (address) {
                                        return StorageSlot.getAddressSlot(_ADMIN_SLOT).value;
                                    }
                                    /**
                                     * @dev Stores a new address in the EIP1967 admin slot.
                                     */
                                    function _setAdmin(address newAdmin) private {
                                        require(newAdmin != address(0), "ERC1967: new admin is the zero address");
                                        StorageSlot.getAddressSlot(_ADMIN_SLOT).value = newAdmin;
                                    }
                                    /**
                                     * @dev Changes the admin of the proxy.
                                     *
                                     * Emits an {AdminChanged} event.
                                     */
                                    function _changeAdmin(address newAdmin) internal {
                                        emit AdminChanged(_getAdmin(), newAdmin);
                                        _setAdmin(newAdmin);
                                    }
                                    /**
                                     * @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
                                     * This is bytes32(uint256(keccak256('eip1967.proxy.beacon')) - 1)) and is validated in the constructor.
                                     */
                                    bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;
                                    /**
                                     * @dev Emitted when the beacon is upgraded.
                                     */
                                    event BeaconUpgraded(address indexed beacon);
                                    /**
                                     * @dev Returns the current beacon.
                                     */
                                    function _getBeacon() internal view returns (address) {
                                        return StorageSlot.getAddressSlot(_BEACON_SLOT).value;
                                    }
                                    /**
                                     * @dev Stores a new beacon in the EIP1967 beacon slot.
                                     */
                                    function _setBeacon(address newBeacon) private {
                                        require(
                                            Address.isContract(newBeacon),
                                            "ERC1967: new beacon is not a contract"
                                        );
                                        require(
                                            Address.isContract(IBeacon(newBeacon).implementation()),
                                            "ERC1967: beacon implementation is not a contract"
                                        );
                                        StorageSlot.getAddressSlot(_BEACON_SLOT).value = newBeacon;
                                    }
                                }
                                // SPDX-License-Identifier: MIT
                                pragma solidity ^0.8.0;
                                /**
                                 * @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
                                 * instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to
                                 * be specified by overriding the virtual {_implementation} function.
                                 *
                                 * Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
                                 * different contract through the {_delegate} function.
                                 *
                                 * The success and return data of the delegated call will be returned back to the caller of the proxy.
                                 */
                                abstract contract Proxy {
                                    /**
                                     * @dev Delegates the current call to `implementation`.
                                     *
                                     * This function does not return to its internall call site, it will return directly to the external caller.
                                     */
                                    function _delegate(address implementation) internal virtual {
                                        // solhint-disable-next-line no-inline-assembly
                                        assembly {
                                            // Copy msg.data. We take full control of memory in this inline assembly
                                            // block because it will not return to Solidity code. We overwrite the
                                            // Solidity scratch pad at memory position 0.
                                            calldatacopy(0, 0, calldatasize())
                                            // Call the implementation.
                                            // out and outsize are 0 because we don't know the size yet.
                                            let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)
                                            // Copy the returned data.
                                            returndatacopy(0, 0, returndatasize())
                                            switch result
                                            // delegatecall returns 0 on error.
                                            case 0 { revert(0, returndatasize()) }
                                            default { return(0, returndatasize()) }
                                        }
                                    }
                                    /**
                                     * @dev This is a virtual function that should be overriden so it returns the address to which the fallback function
                                     * and {_fallback} should delegate.
                                     */
                                    function _implementation() internal view virtual returns (address);
                                    /**
                                     * @dev Delegates the current call to the address returned by `_implementation()`.
                                     *
                                     * This function does not return to its internall call site, it will return directly to the external caller.
                                     */
                                    function _fallback() internal virtual {
                                        _beforeFallback();
                                        _delegate(_implementation());
                                    }
                                    /**
                                     * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other
                                     * function in the contract matches the call data.
                                     */
                                    fallback () external payable virtual {
                                        _fallback();
                                    }
                                    /**
                                     * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
                                     * is empty.
                                     */
                                    receive () external payable virtual {
                                        _fallback();
                                    }
                                    /**
                                     * @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback`
                                     * call, or as part of the Solidity `fallback` or `receive` functions.
                                     *
                                     * If overriden should call `super._beforeFallback()`.
                                     */
                                    function _beforeFallback() internal virtual {
                                    }
                                }
                                // SPDX-License-Identifier: MIT
                                pragma solidity ^0.8.0;
                                /**
                                 * @dev This is the interface that {BeaconProxy} expects of its beacon.
                                 */
                                interface IBeacon {
                                    /**
                                     * @dev Must return an address that can be used as a delegate call target.
                                     *
                                     * {BeaconProxy} will check that this address is a contract.
                                     */
                                    function implementation() external view returns (address);
                                }
                                // SPDX-License-Identifier: MIT
                                pragma solidity ^0.8.0;
                                /**
                                 * @dev Collection of functions related to the address type
                                 */
                                library Address {
                                    /**
                                     * @dev Returns true if `account` is a contract.
                                     *
                                     * [IMPORTANT]
                                     * ====
                                     * It is unsafe to assume that an address for which this function returns
                                     * false is an externally-owned account (EOA) and not a contract.
                                     *
                                     * Among others, `isContract` will return false for the following
                                     * types of addresses:
                                     *
                                     *  - an externally-owned account
                                     *  - a contract in construction
                                     *  - an address where a contract will be created
                                     *  - an address where a contract lived, but was destroyed
                                     * ====
                                     */
                                    function isContract(address account) internal view returns (bool) {
                                        // This method relies on extcodesize, which returns 0 for contracts in
                                        // construction, since the code is only stored at the end of the
                                        // constructor execution.
                                        uint256 size;
                                        // solhint-disable-next-line no-inline-assembly
                                        assembly { size := extcodesize(account) }
                                        return size > 0;
                                    }
                                    /**
                                     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
                                     * `recipient`, forwarding all available gas and reverting on errors.
                                     *
                                     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
                                     * of certain opcodes, possibly making contracts go over the 2300 gas limit
                                     * imposed by `transfer`, making them unable to receive funds via
                                     * `transfer`. {sendValue} removes this limitation.
                                     *
                                     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
                                     *
                                     * IMPORTANT: because control is transferred to `recipient`, care must be
                                     * taken to not create reentrancy vulnerabilities. Consider using
                                     * {ReentrancyGuard} or the
                                     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
                                     */
                                    function sendValue(address payable recipient, uint256 amount) internal {
                                        require(address(this).balance >= amount, "Address: insufficient balance");
                                        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
                                        (bool success, ) = recipient.call{ value: amount }("");
                                        require(success, "Address: unable to send value, recipient may have reverted");
                                    }
                                    /**
                                     * @dev Performs a Solidity function call using a low level `call`. A
                                     * plain`call` is an unsafe replacement for a function call: use this
                                     * function instead.
                                     *
                                     * If `target` reverts with a revert reason, it is bubbled up by this
                                     * function (like regular Solidity function calls).
                                     *
                                     * Returns the raw returned data. To convert to the expected return value,
                                     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
                                     *
                                     * Requirements:
                                     *
                                     * - `target` must be a contract.
                                     * - calling `target` with `data` must not revert.
                                     *
                                     * _Available since v3.1._
                                     */
                                    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
                                      return functionCall(target, data, "Address: low-level call failed");
                                    }
                                    /**
                                     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
                                     * `errorMessage` as a fallback revert reason when `target` reverts.
                                     *
                                     * _Available since v3.1._
                                     */
                                    function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
                                        return functionCallWithValue(target, data, 0, errorMessage);
                                    }
                                    /**
                                     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                                     * but also transferring `value` wei to `target`.
                                     *
                                     * Requirements:
                                     *
                                     * - the calling contract must have an ETH balance of at least `value`.
                                     * - the called Solidity function must be `payable`.
                                     *
                                     * _Available since v3.1._
                                     */
                                    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
                                        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
                                    }
                                    /**
                                     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
                                     * with `errorMessage` as a fallback revert reason when `target` reverts.
                                     *
                                     * _Available since v3.1._
                                     */
                                    function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
                                        require(address(this).balance >= value, "Address: insufficient balance for call");
                                        require(isContract(target), "Address: call to non-contract");
                                        // solhint-disable-next-line avoid-low-level-calls
                                        (bool success, bytes memory returndata) = target.call{ value: value }(data);
                                        return _verifyCallResult(success, returndata, errorMessage);
                                    }
                                    /**
                                     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                                     * but performing a static call.
                                     *
                                     * _Available since v3.3._
                                     */
                                    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                                        return functionStaticCall(target, data, "Address: low-level static call failed");
                                    }
                                    /**
                                     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                                     * but performing a static call.
                                     *
                                     * _Available since v3.3._
                                     */
                                    function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
                                        require(isContract(target), "Address: static call to non-contract");
                                        // solhint-disable-next-line avoid-low-level-calls
                                        (bool success, bytes memory returndata) = target.staticcall(data);
                                        return _verifyCallResult(success, returndata, errorMessage);
                                    }
                                    /**
                                     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                                     * but performing a delegate call.
                                     *
                                     * _Available since v3.4._
                                     */
                                    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
                                        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
                                    }
                                    /**
                                     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                                     * but performing a delegate call.
                                     *
                                     * _Available since v3.4._
                                     */
                                    function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
                                        require(isContract(target), "Address: delegate call to non-contract");
                                        // solhint-disable-next-line avoid-low-level-calls
                                        (bool success, bytes memory returndata) = target.delegatecall(data);
                                        return _verifyCallResult(success, returndata, errorMessage);
                                    }
                                    function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
                                        if (success) {
                                            return returndata;
                                        } else {
                                            // Look for revert reason and bubble it up if present
                                            if (returndata.length > 0) {
                                                // The easiest way to bubble the revert reason is using memory via assembly
                                                // solhint-disable-next-line no-inline-assembly
                                                assembly {
                                                    let returndata_size := mload(returndata)
                                                    revert(add(32, returndata), returndata_size)
                                                }
                                            } else {
                                                revert(errorMessage);
                                            }
                                        }
                                    }
                                }
                                // SPDX-License-Identifier: MIT
                                pragma solidity ^0.8.0;
                                /**
                                 * @dev Library for reading and writing primitive types to specific storage slots.
                                 *
                                 * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
                                 * This library helps with reading and writing to such slots without the need for inline assembly.
                                 *
                                 * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
                                 *
                                 * Example usage to set ERC1967 implementation slot:
                                 * ```
                                 * contract ERC1967 {
                                 *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
                                 *
                                 *     function _getImplementation() internal view returns (address) {
                                 *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
                                 *     }
                                 *
                                 *     function _setImplementation(address newImplementation) internal {
                                 *         require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
                                 *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
                                 *     }
                                 * }
                                 * ```
                                 *
                                 * _Available since v4.1 for `address`, `bool`, `bytes32`, and `uint256`._
                                 */
                                library StorageSlot {
                                    struct AddressSlot {
                                        address value;
                                    }
                                    struct BooleanSlot {
                                        bool value;
                                    }
                                    struct Bytes32Slot {
                                        bytes32 value;
                                    }
                                    struct Uint256Slot {
                                        uint256 value;
                                    }
                                    /**
                                     * @dev Returns an `AddressSlot` with member `value` located at `slot`.
                                     */
                                    function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
                                        assembly {
                                            r.slot := slot
                                        }
                                    }
                                    /**
                                     * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
                                     */
                                    function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
                                        assembly {
                                            r.slot := slot
                                        }
                                    }
                                    /**
                                     * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
                                     */
                                    function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
                                        assembly {
                                            r.slot := slot
                                        }
                                    }
                                    /**
                                     * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
                                     */
                                    function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
                                        assembly {
                                            r.slot := slot
                                        }
                                    }
                                }
                                

                                File 2 of 4: Wormhole
                                // contracts/Wormhole.sol
                                // SPDX-License-Identifier: Apache 2
                                pragma solidity ^0.8.0;
                                import "@openzeppelin/contracts/proxy/ERC1967/ERC1967Proxy.sol";
                                contract Wormhole is ERC1967Proxy {
                                    constructor (address implementation, bytes memory initData) ERC1967Proxy(
                                        implementation,
                                        initData
                                    ) { }
                                }// SPDX-License-Identifier: MIT
                                pragma solidity ^0.8.0;
                                import "../Proxy.sol";
                                import "./ERC1967Upgrade.sol";
                                /**
                                 * @dev This contract implements an upgradeable proxy. It is upgradeable because calls are delegated to an
                                 * implementation address that can be changed. This address is stored in storage in the location specified by
                                 * https://eips.ethereum.org/EIPS/eip-1967[EIP1967], so that it doesn't conflict with the storage layout of the
                                 * implementation behind the proxy.
                                 */
                                contract ERC1967Proxy is Proxy, ERC1967Upgrade {
                                    /**
                                     * @dev Initializes the upgradeable proxy with an initial implementation specified by `_logic`.
                                     *
                                     * If `_data` is nonempty, it's used as data in a delegate call to `_logic`. This will typically be an encoded
                                     * function call, and allows initializating the storage of the proxy like a Solidity constructor.
                                     */
                                    constructor(address _logic, bytes memory _data) payable {
                                        assert(_IMPLEMENTATION_SLOT == bytes32(uint256(keccak256("eip1967.proxy.implementation")) - 1));
                                        _upgradeToAndCall(_logic, _data, false);
                                    }
                                    /**
                                     * @dev Returns the current implementation address.
                                     */
                                    function _implementation() internal view virtual override returns (address impl) {
                                        return ERC1967Upgrade._getImplementation();
                                    }
                                }
                                // SPDX-License-Identifier: MIT
                                pragma solidity ^0.8.2;
                                import "../beacon/IBeacon.sol";
                                import "../../utils/Address.sol";
                                import "../../utils/StorageSlot.sol";
                                /**
                                 * @dev This abstract contract provides getters and event emitting update functions for
                                 * https://eips.ethereum.org/EIPS/eip-1967[EIP1967] slots.
                                 *
                                 * _Available since v4.1._
                                 *
                                 * @custom:oz-upgrades-unsafe-allow delegatecall
                                 */
                                abstract contract ERC1967Upgrade {
                                    // This is the keccak-256 hash of "eip1967.proxy.rollback" subtracted by 1
                                    bytes32 private constant _ROLLBACK_SLOT = 0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;
                                    /**
                                     * @dev Storage slot with the address of the current implementation.
                                     * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
                                     * validated in the constructor.
                                     */
                                    bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
                                    /**
                                     * @dev Emitted when the implementation is upgraded.
                                     */
                                    event Upgraded(address indexed implementation);
                                    /**
                                     * @dev Returns the current implementation address.
                                     */
                                    function _getImplementation() internal view returns (address) {
                                        return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
                                    }
                                    /**
                                     * @dev Stores a new address in the EIP1967 implementation slot.
                                     */
                                    function _setImplementation(address newImplementation) private {
                                        require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
                                        StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
                                    }
                                    /**
                                     * @dev Perform implementation upgrade
                                     *
                                     * Emits an {Upgraded} event.
                                     */
                                    function _upgradeTo(address newImplementation) internal {
                                        _setImplementation(newImplementation);
                                        emit Upgraded(newImplementation);
                                    }
                                    /**
                                     * @dev Perform implementation upgrade with additional setup call.
                                     *
                                     * Emits an {Upgraded} event.
                                     */
                                    function _upgradeToAndCall(address newImplementation, bytes memory data, bool forceCall) internal {
                                        _setImplementation(newImplementation);
                                        emit Upgraded(newImplementation);
                                        if (data.length > 0 || forceCall) {
                                            Address.functionDelegateCall(newImplementation, data);
                                        }
                                    }
                                    /**
                                     * @dev Perform implementation upgrade with security checks for UUPS proxies, and additional setup call.
                                     *
                                     * Emits an {Upgraded} event.
                                     */
                                    function _upgradeToAndCallSecure(address newImplementation, bytes memory data, bool forceCall) internal {
                                        address oldImplementation = _getImplementation();
                                        // Initial upgrade and setup call
                                        _setImplementation(newImplementation);
                                        if (data.length > 0 || forceCall) {
                                            Address.functionDelegateCall(newImplementation, data);
                                        }
                                        // Perform rollback test if not already in progress
                                        StorageSlot.BooleanSlot storage rollbackTesting = StorageSlot.getBooleanSlot(_ROLLBACK_SLOT);
                                        if (!rollbackTesting.value) {
                                            // Trigger rollback using upgradeTo from the new implementation
                                            rollbackTesting.value = true;
                                            Address.functionDelegateCall(
                                                newImplementation,
                                                abi.encodeWithSignature(
                                                    "upgradeTo(address)",
                                                    oldImplementation
                                                )
                                            );
                                            rollbackTesting.value = false;
                                            // Check rollback was effective
                                            require(oldImplementation == _getImplementation(), "ERC1967Upgrade: upgrade breaks further upgrades");
                                            // Finally reset to the new implementation and log the upgrade
                                            _setImplementation(newImplementation);
                                            emit Upgraded(newImplementation);
                                        }
                                    }
                                    /**
                                     * @dev Perform beacon upgrade with additional setup call. Note: This upgrades the address of the beacon, it does
                                     * not upgrade the implementation contained in the beacon (see {UpgradeableBeacon-_setImplementation} for that).
                                     *
                                     * Emits a {BeaconUpgraded} event.
                                     */
                                    function _upgradeBeaconToAndCall(address newBeacon, bytes memory data, bool forceCall) internal {
                                        _setBeacon(newBeacon);
                                        emit BeaconUpgraded(newBeacon);
                                        if (data.length > 0 || forceCall) {
                                            Address.functionDelegateCall(IBeacon(newBeacon).implementation(), data);
                                        }
                                    }
                                    /**
                                     * @dev Storage slot with the admin of the contract.
                                     * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
                                     * validated in the constructor.
                                     */
                                    bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
                                    /**
                                     * @dev Emitted when the admin account has changed.
                                     */
                                    event AdminChanged(address previousAdmin, address newAdmin);
                                    /**
                                     * @dev Returns the current admin.
                                     */
                                    function _getAdmin() internal view returns (address) {
                                        return StorageSlot.getAddressSlot(_ADMIN_SLOT).value;
                                    }
                                    /**
                                     * @dev Stores a new address in the EIP1967 admin slot.
                                     */
                                    function _setAdmin(address newAdmin) private {
                                        require(newAdmin != address(0), "ERC1967: new admin is the zero address");
                                        StorageSlot.getAddressSlot(_ADMIN_SLOT).value = newAdmin;
                                    }
                                    /**
                                     * @dev Changes the admin of the proxy.
                                     *
                                     * Emits an {AdminChanged} event.
                                     */
                                    function _changeAdmin(address newAdmin) internal {
                                        emit AdminChanged(_getAdmin(), newAdmin);
                                        _setAdmin(newAdmin);
                                    }
                                    /**
                                     * @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
                                     * This is bytes32(uint256(keccak256('eip1967.proxy.beacon')) - 1)) and is validated in the constructor.
                                     */
                                    bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;
                                    /**
                                     * @dev Emitted when the beacon is upgraded.
                                     */
                                    event BeaconUpgraded(address indexed beacon);
                                    /**
                                     * @dev Returns the current beacon.
                                     */
                                    function _getBeacon() internal view returns (address) {
                                        return StorageSlot.getAddressSlot(_BEACON_SLOT).value;
                                    }
                                    /**
                                     * @dev Stores a new beacon in the EIP1967 beacon slot.
                                     */
                                    function _setBeacon(address newBeacon) private {
                                        require(
                                            Address.isContract(newBeacon),
                                            "ERC1967: new beacon is not a contract"
                                        );
                                        require(
                                            Address.isContract(IBeacon(newBeacon).implementation()),
                                            "ERC1967: beacon implementation is not a contract"
                                        );
                                        StorageSlot.getAddressSlot(_BEACON_SLOT).value = newBeacon;
                                    }
                                }
                                // SPDX-License-Identifier: MIT
                                pragma solidity ^0.8.0;
                                /**
                                 * @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
                                 * instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to
                                 * be specified by overriding the virtual {_implementation} function.
                                 *
                                 * Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
                                 * different contract through the {_delegate} function.
                                 *
                                 * The success and return data of the delegated call will be returned back to the caller of the proxy.
                                 */
                                abstract contract Proxy {
                                    /**
                                     * @dev Delegates the current call to `implementation`.
                                     *
                                     * This function does not return to its internall call site, it will return directly to the external caller.
                                     */
                                    function _delegate(address implementation) internal virtual {
                                        // solhint-disable-next-line no-inline-assembly
                                        assembly {
                                            // Copy msg.data. We take full control of memory in this inline assembly
                                            // block because it will not return to Solidity code. We overwrite the
                                            // Solidity scratch pad at memory position 0.
                                            calldatacopy(0, 0, calldatasize())
                                            // Call the implementation.
                                            // out and outsize are 0 because we don't know the size yet.
                                            let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)
                                            // Copy the returned data.
                                            returndatacopy(0, 0, returndatasize())
                                            switch result
                                            // delegatecall returns 0 on error.
                                            case 0 { revert(0, returndatasize()) }
                                            default { return(0, returndatasize()) }
                                        }
                                    }
                                    /**
                                     * @dev This is a virtual function that should be overriden so it returns the address to which the fallback function
                                     * and {_fallback} should delegate.
                                     */
                                    function _implementation() internal view virtual returns (address);
                                    /**
                                     * @dev Delegates the current call to the address returned by `_implementation()`.
                                     *
                                     * This function does not return to its internall call site, it will return directly to the external caller.
                                     */
                                    function _fallback() internal virtual {
                                        _beforeFallback();
                                        _delegate(_implementation());
                                    }
                                    /**
                                     * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other
                                     * function in the contract matches the call data.
                                     */
                                    fallback () external payable virtual {
                                        _fallback();
                                    }
                                    /**
                                     * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
                                     * is empty.
                                     */
                                    receive () external payable virtual {
                                        _fallback();
                                    }
                                    /**
                                     * @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback`
                                     * call, or as part of the Solidity `fallback` or `receive` functions.
                                     *
                                     * If overriden should call `super._beforeFallback()`.
                                     */
                                    function _beforeFallback() internal virtual {
                                    }
                                }
                                // SPDX-License-Identifier: MIT
                                pragma solidity ^0.8.0;
                                /**
                                 * @dev This is the interface that {BeaconProxy} expects of its beacon.
                                 */
                                interface IBeacon {
                                    /**
                                     * @dev Must return an address that can be used as a delegate call target.
                                     *
                                     * {BeaconProxy} will check that this address is a contract.
                                     */
                                    function implementation() external view returns (address);
                                }
                                // SPDX-License-Identifier: MIT
                                pragma solidity ^0.8.0;
                                /**
                                 * @dev Collection of functions related to the address type
                                 */
                                library Address {
                                    /**
                                     * @dev Returns true if `account` is a contract.
                                     *
                                     * [IMPORTANT]
                                     * ====
                                     * It is unsafe to assume that an address for which this function returns
                                     * false is an externally-owned account (EOA) and not a contract.
                                     *
                                     * Among others, `isContract` will return false for the following
                                     * types of addresses:
                                     *
                                     *  - an externally-owned account
                                     *  - a contract in construction
                                     *  - an address where a contract will be created
                                     *  - an address where a contract lived, but was destroyed
                                     * ====
                                     */
                                    function isContract(address account) internal view returns (bool) {
                                        // This method relies on extcodesize, which returns 0 for contracts in
                                        // construction, since the code is only stored at the end of the
                                        // constructor execution.
                                        uint256 size;
                                        // solhint-disable-next-line no-inline-assembly
                                        assembly { size := extcodesize(account) }
                                        return size > 0;
                                    }
                                    /**
                                     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
                                     * `recipient`, forwarding all available gas and reverting on errors.
                                     *
                                     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
                                     * of certain opcodes, possibly making contracts go over the 2300 gas limit
                                     * imposed by `transfer`, making them unable to receive funds via
                                     * `transfer`. {sendValue} removes this limitation.
                                     *
                                     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
                                     *
                                     * IMPORTANT: because control is transferred to `recipient`, care must be
                                     * taken to not create reentrancy vulnerabilities. Consider using
                                     * {ReentrancyGuard} or the
                                     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
                                     */
                                    function sendValue(address payable recipient, uint256 amount) internal {
                                        require(address(this).balance >= amount, "Address: insufficient balance");
                                        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
                                        (bool success, ) = recipient.call{ value: amount }("");
                                        require(success, "Address: unable to send value, recipient may have reverted");
                                    }
                                    /**
                                     * @dev Performs a Solidity function call using a low level `call`. A
                                     * plain`call` is an unsafe replacement for a function call: use this
                                     * function instead.
                                     *
                                     * If `target` reverts with a revert reason, it is bubbled up by this
                                     * function (like regular Solidity function calls).
                                     *
                                     * Returns the raw returned data. To convert to the expected return value,
                                     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
                                     *
                                     * Requirements:
                                     *
                                     * - `target` must be a contract.
                                     * - calling `target` with `data` must not revert.
                                     *
                                     * _Available since v3.1._
                                     */
                                    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
                                      return functionCall(target, data, "Address: low-level call failed");
                                    }
                                    /**
                                     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
                                     * `errorMessage` as a fallback revert reason when `target` reverts.
                                     *
                                     * _Available since v3.1._
                                     */
                                    function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
                                        return functionCallWithValue(target, data, 0, errorMessage);
                                    }
                                    /**
                                     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                                     * but also transferring `value` wei to `target`.
                                     *
                                     * Requirements:
                                     *
                                     * - the calling contract must have an ETH balance of at least `value`.
                                     * - the called Solidity function must be `payable`.
                                     *
                                     * _Available since v3.1._
                                     */
                                    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
                                        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
                                    }
                                    /**
                                     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
                                     * with `errorMessage` as a fallback revert reason when `target` reverts.
                                     *
                                     * _Available since v3.1._
                                     */
                                    function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
                                        require(address(this).balance >= value, "Address: insufficient balance for call");
                                        require(isContract(target), "Address: call to non-contract");
                                        // solhint-disable-next-line avoid-low-level-calls
                                        (bool success, bytes memory returndata) = target.call{ value: value }(data);
                                        return _verifyCallResult(success, returndata, errorMessage);
                                    }
                                    /**
                                     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                                     * but performing a static call.
                                     *
                                     * _Available since v3.3._
                                     */
                                    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                                        return functionStaticCall(target, data, "Address: low-level static call failed");
                                    }
                                    /**
                                     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                                     * but performing a static call.
                                     *
                                     * _Available since v3.3._
                                     */
                                    function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
                                        require(isContract(target), "Address: static call to non-contract");
                                        // solhint-disable-next-line avoid-low-level-calls
                                        (bool success, bytes memory returndata) = target.staticcall(data);
                                        return _verifyCallResult(success, returndata, errorMessage);
                                    }
                                    /**
                                     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                                     * but performing a delegate call.
                                     *
                                     * _Available since v3.4._
                                     */
                                    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
                                        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
                                    }
                                    /**
                                     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                                     * but performing a delegate call.
                                     *
                                     * _Available since v3.4._
                                     */
                                    function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
                                        require(isContract(target), "Address: delegate call to non-contract");
                                        // solhint-disable-next-line avoid-low-level-calls
                                        (bool success, bytes memory returndata) = target.delegatecall(data);
                                        return _verifyCallResult(success, returndata, errorMessage);
                                    }
                                    function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
                                        if (success) {
                                            return returndata;
                                        } else {
                                            // Look for revert reason and bubble it up if present
                                            if (returndata.length > 0) {
                                                // The easiest way to bubble the revert reason is using memory via assembly
                                                // solhint-disable-next-line no-inline-assembly
                                                assembly {
                                                    let returndata_size := mload(returndata)
                                                    revert(add(32, returndata), returndata_size)
                                                }
                                            } else {
                                                revert(errorMessage);
                                            }
                                        }
                                    }
                                }
                                // SPDX-License-Identifier: MIT
                                pragma solidity ^0.8.0;
                                /**
                                 * @dev Library for reading and writing primitive types to specific storage slots.
                                 *
                                 * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
                                 * This library helps with reading and writing to such slots without the need for inline assembly.
                                 *
                                 * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
                                 *
                                 * Example usage to set ERC1967 implementation slot:
                                 * ```
                                 * contract ERC1967 {
                                 *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
                                 *
                                 *     function _getImplementation() internal view returns (address) {
                                 *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
                                 *     }
                                 *
                                 *     function _setImplementation(address newImplementation) internal {
                                 *         require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
                                 *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
                                 *     }
                                 * }
                                 * ```
                                 *
                                 * _Available since v4.1 for `address`, `bool`, `bytes32`, and `uint256`._
                                 */
                                library StorageSlot {
                                    struct AddressSlot {
                                        address value;
                                    }
                                    struct BooleanSlot {
                                        bool value;
                                    }
                                    struct Bytes32Slot {
                                        bytes32 value;
                                    }
                                    struct Uint256Slot {
                                        uint256 value;
                                    }
                                    /**
                                     * @dev Returns an `AddressSlot` with member `value` located at `slot`.
                                     */
                                    function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
                                        assembly {
                                            r.slot := slot
                                        }
                                    }
                                    /**
                                     * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
                                     */
                                    function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
                                        assembly {
                                            r.slot := slot
                                        }
                                    }
                                    /**
                                     * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
                                     */
                                    function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
                                        assembly {
                                            r.slot := slot
                                        }
                                    }
                                    /**
                                     * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
                                     */
                                    function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
                                        assembly {
                                            r.slot := slot
                                        }
                                    }
                                }
                                

                                File 3 of 4: BridgeImplementation
                                // 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 ^0.8.2;
                                import "../beacon/IBeacon.sol";
                                import "../../utils/Address.sol";
                                import "../../utils/StorageSlot.sol";
                                /**
                                 * @dev This abstract contract provides getters and event emitting update functions for
                                 * https://eips.ethereum.org/EIPS/eip-1967[EIP1967] slots.
                                 *
                                 * _Available since v4.1._
                                 *
                                 * @custom:oz-upgrades-unsafe-allow delegatecall
                                 */
                                abstract contract ERC1967Upgrade {
                                    // This is the keccak-256 hash of "eip1967.proxy.rollback" subtracted by 1
                                    bytes32 private constant _ROLLBACK_SLOT = 0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;
                                    /**
                                     * @dev Storage slot with the address of the current implementation.
                                     * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
                                     * validated in the constructor.
                                     */
                                    bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
                                    /**
                                     * @dev Emitted when the implementation is upgraded.
                                     */
                                    event Upgraded(address indexed implementation);
                                    /**
                                     * @dev Returns the current implementation address.
                                     */
                                    function _getImplementation() internal view returns (address) {
                                        return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
                                    }
                                    /**
                                     * @dev Stores a new address in the EIP1967 implementation slot.
                                     */
                                    function _setImplementation(address newImplementation) private {
                                        require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
                                        StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
                                    }
                                    /**
                                     * @dev Perform implementation upgrade
                                     *
                                     * Emits an {Upgraded} event.
                                     */
                                    function _upgradeTo(address newImplementation) internal {
                                        _setImplementation(newImplementation);
                                        emit Upgraded(newImplementation);
                                    }
                                    /**
                                     * @dev Perform implementation upgrade with additional setup call.
                                     *
                                     * Emits an {Upgraded} event.
                                     */
                                    function _upgradeToAndCall(
                                        address newImplementation,
                                        bytes memory data,
                                        bool forceCall
                                    ) internal {
                                        _upgradeTo(newImplementation);
                                        if (data.length > 0 || forceCall) {
                                            Address.functionDelegateCall(newImplementation, data);
                                        }
                                    }
                                    /**
                                     * @dev Perform implementation upgrade with security checks for UUPS proxies, and additional setup call.
                                     *
                                     * Emits an {Upgraded} event.
                                     */
                                    function _upgradeToAndCallSecure(
                                        address newImplementation,
                                        bytes memory data,
                                        bool forceCall
                                    ) internal {
                                        address oldImplementation = _getImplementation();
                                        // Initial upgrade and setup call
                                        _setImplementation(newImplementation);
                                        if (data.length > 0 || forceCall) {
                                            Address.functionDelegateCall(newImplementation, data);
                                        }
                                        // Perform rollback test if not already in progress
                                        StorageSlot.BooleanSlot storage rollbackTesting = StorageSlot.getBooleanSlot(_ROLLBACK_SLOT);
                                        if (!rollbackTesting.value) {
                                            // Trigger rollback using upgradeTo from the new implementation
                                            rollbackTesting.value = true;
                                            Address.functionDelegateCall(
                                                newImplementation,
                                                abi.encodeWithSignature("upgradeTo(address)", oldImplementation)
                                            );
                                            rollbackTesting.value = false;
                                            // Check rollback was effective
                                            require(oldImplementation == _getImplementation(), "ERC1967Upgrade: upgrade breaks further upgrades");
                                            // Finally reset to the new implementation and log the upgrade
                                            _upgradeTo(newImplementation);
                                        }
                                    }
                                    /**
                                     * @dev Storage slot with the admin of the contract.
                                     * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
                                     * validated in the constructor.
                                     */
                                    bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
                                    /**
                                     * @dev Emitted when the admin account has changed.
                                     */
                                    event AdminChanged(address previousAdmin, address newAdmin);
                                    /**
                                     * @dev Returns the current admin.
                                     */
                                    function _getAdmin() internal view returns (address) {
                                        return StorageSlot.getAddressSlot(_ADMIN_SLOT).value;
                                    }
                                    /**
                                     * @dev Stores a new address in the EIP1967 admin slot.
                                     */
                                    function _setAdmin(address newAdmin) private {
                                        require(newAdmin != address(0), "ERC1967: new admin is the zero address");
                                        StorageSlot.getAddressSlot(_ADMIN_SLOT).value = newAdmin;
                                    }
                                    /**
                                     * @dev Changes the admin of the proxy.
                                     *
                                     * Emits an {AdminChanged} event.
                                     */
                                    function _changeAdmin(address newAdmin) internal {
                                        emit AdminChanged(_getAdmin(), newAdmin);
                                        _setAdmin(newAdmin);
                                    }
                                    /**
                                     * @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
                                     * This is bytes32(uint256(keccak256('eip1967.proxy.beacon')) - 1)) and is validated in the constructor.
                                     */
                                    bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;
                                    /**
                                     * @dev Emitted when the beacon is upgraded.
                                     */
                                    event BeaconUpgraded(address indexed beacon);
                                    /**
                                     * @dev Returns the current beacon.
                                     */
                                    function _getBeacon() internal view returns (address) {
                                        return StorageSlot.getAddressSlot(_BEACON_SLOT).value;
                                    }
                                    /**
                                     * @dev Stores a new beacon in the EIP1967 beacon slot.
                                     */
                                    function _setBeacon(address newBeacon) private {
                                        require(Address.isContract(newBeacon), "ERC1967: new beacon is not a contract");
                                        require(
                                            Address.isContract(IBeacon(newBeacon).implementation()),
                                            "ERC1967: beacon implementation is not a contract"
                                        );
                                        StorageSlot.getAddressSlot(_BEACON_SLOT).value = newBeacon;
                                    }
                                    /**
                                     * @dev Perform beacon upgrade with additional setup call. Note: This upgrades the address of the beacon, it does
                                     * not upgrade the implementation contained in the beacon (see {UpgradeableBeacon-_setImplementation} for that).
                                     *
                                     * Emits a {BeaconUpgraded} event.
                                     */
                                    function _upgradeBeaconToAndCall(
                                        address newBeacon,
                                        bytes memory data,
                                        bool forceCall
                                    ) internal {
                                        _setBeacon(newBeacon);
                                        emit BeaconUpgraded(newBeacon);
                                        if (data.length > 0 || forceCall) {
                                            Address.functionDelegateCall(IBeacon(newBeacon).implementation(), data);
                                        }
                                    }
                                }
                                // SPDX-License-Identifier: MIT
                                pragma solidity ^0.8.0;
                                /**
                                 * @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
                                 * instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to
                                 * be specified by overriding the virtual {_implementation} function.
                                 *
                                 * Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
                                 * different contract through the {_delegate} function.
                                 *
                                 * The success and return data of the delegated call will be returned back to the caller of the proxy.
                                 */
                                abstract contract Proxy {
                                    /**
                                     * @dev Delegates the current call to `implementation`.
                                     *
                                     * This function does not return to its internall call site, it will return directly to the external caller.
                                     */
                                    function _delegate(address implementation) internal virtual {
                                        assembly {
                                            // Copy msg.data. We take full control of memory in this inline assembly
                                            // block because it will not return to Solidity code. We overwrite the
                                            // Solidity scratch pad at memory position 0.
                                            calldatacopy(0, 0, calldatasize())
                                            // Call the implementation.
                                            // out and outsize are 0 because we don't know the size yet.
                                            let result := delegatecall(gas(), implementation, 0, calldatasize(), 0, 0)
                                            // Copy the returned data.
                                            returndatacopy(0, 0, returndatasize())
                                            switch result
                                            // delegatecall returns 0 on error.
                                            case 0 {
                                                revert(0, returndatasize())
                                            }
                                            default {
                                                return(0, returndatasize())
                                            }
                                        }
                                    }
                                    /**
                                     * @dev This is a virtual function that should be overriden so it returns the address to which the fallback function
                                     * and {_fallback} should delegate.
                                     */
                                    function _implementation() internal view virtual returns (address);
                                    /**
                                     * @dev Delegates the current call to the address returned by `_implementation()`.
                                     *
                                     * This function does not return to its internall call site, it will return directly to the external caller.
                                     */
                                    function _fallback() internal virtual {
                                        _beforeFallback();
                                        _delegate(_implementation());
                                    }
                                    /**
                                     * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if no other
                                     * function in the contract matches the call data.
                                     */
                                    fallback() external payable virtual {
                                        _fallback();
                                    }
                                    /**
                                     * @dev Fallback function that delegates calls to the address returned by `_implementation()`. Will run if call data
                                     * is empty.
                                     */
                                    receive() external payable virtual {
                                        _fallback();
                                    }
                                    /**
                                     * @dev Hook that is called before falling back to the implementation. Can happen as part of a manual `_fallback`
                                     * call, or as part of the Solidity `fallback` or `receive` functions.
                                     *
                                     * If overriden should call `super._beforeFallback()`.
                                     */
                                    function _beforeFallback() internal virtual {}
                                }
                                // SPDX-License-Identifier: MIT
                                pragma solidity ^0.8.0;
                                import "./IBeacon.sol";
                                import "../Proxy.sol";
                                import "../ERC1967/ERC1967Upgrade.sol";
                                /**
                                 * @dev This contract implements a proxy that gets the implementation address for each call from a {UpgradeableBeacon}.
                                 *
                                 * The beacon address is stored in storage slot `uint256(keccak256('eip1967.proxy.beacon')) - 1`, so that it doesn't
                                 * conflict with the storage layout of the implementation behind the proxy.
                                 *
                                 * _Available since v3.4._
                                 */
                                contract BeaconProxy is Proxy, ERC1967Upgrade {
                                    /**
                                     * @dev Initializes the proxy with `beacon`.
                                     *
                                     * If `data` is nonempty, it's used as data in a delegate call to the implementation returned by the beacon. This
                                     * will typically be an encoded function call, and allows initializating the storage of the proxy like a Solidity
                                     * constructor.
                                     *
                                     * Requirements:
                                     *
                                     * - `beacon` must be a contract with the interface {IBeacon}.
                                     */
                                    constructor(address beacon, bytes memory data) payable {
                                        assert(_BEACON_SLOT == bytes32(uint256(keccak256("eip1967.proxy.beacon")) - 1));
                                        _upgradeBeaconToAndCall(beacon, data, false);
                                    }
                                    /**
                                     * @dev Returns the current beacon address.
                                     */
                                    function _beacon() internal view virtual returns (address) {
                                        return _getBeacon();
                                    }
                                    /**
                                     * @dev Returns the current implementation address of the associated beacon.
                                     */
                                    function _implementation() internal view virtual override returns (address) {
                                        return IBeacon(_getBeacon()).implementation();
                                    }
                                    /**
                                     * @dev Changes the proxy to use a new beacon. Deprecated: see {_upgradeBeaconToAndCall}.
                                     *
                                     * If `data` is nonempty, it's used as data in a delegate call to the implementation returned by the beacon.
                                     *
                                     * Requirements:
                                     *
                                     * - `beacon` must be a contract.
                                     * - The implementation returned by `beacon` must be a contract.
                                     */
                                    function _setBeacon(address beacon, bytes memory data) internal virtual {
                                        _upgradeBeaconToAndCall(beacon, data, false);
                                    }
                                }
                                // SPDX-License-Identifier: MIT
                                pragma solidity ^0.8.0;
                                /**
                                 * @dev This is the interface that {BeaconProxy} expects of its beacon.
                                 */
                                interface IBeacon {
                                    /**
                                     * @dev Must return an address that can be used as a delegate call target.
                                     *
                                     * {BeaconProxy} will check that this address is a contract.
                                     */
                                    function implementation() external view returns (address);
                                }
                                // SPDX-License-Identifier: MIT
                                pragma solidity ^0.8.0;
                                /**
                                 * @dev Contract module that helps prevent reentrant calls to a function.
                                 *
                                 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
                                 * available, which can be applied to functions to make sure there are no nested
                                 * (reentrant) calls to them.
                                 *
                                 * Note that because there is a single `nonReentrant` guard, functions marked as
                                 * `nonReentrant` may not call one another. This can be worked around by making
                                 * those functions `private`, and then adding `external` `nonReentrant` entry
                                 * points to them.
                                 *
                                 * TIP: If you would like to learn more about reentrancy and alternative ways
                                 * to protect against it, check out our blog post
                                 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
                                 */
                                abstract contract ReentrancyGuard {
                                    // Booleans are more expensive than uint256 or any type that takes up a full
                                    // word because each write operation emits an extra SLOAD to first read the
                                    // slot's contents, replace the bits taken up by the boolean, and then write
                                    // back. This is the compiler's defense against contract upgrades and
                                    // pointer aliasing, and it cannot be disabled.
                                    // The values being non-zero value makes deployment a bit more expensive,
                                    // but in exchange the refund on every call to nonReentrant will be lower in
                                    // amount. Since refunds are capped to a percentage of the total
                                    // transaction's gas, it is best to keep them low in cases like this one, to
                                    // increase the likelihood of the full refund coming into effect.
                                    uint256 private constant _NOT_ENTERED = 1;
                                    uint256 private constant _ENTERED = 2;
                                    uint256 private _status;
                                    constructor() {
                                        _status = _NOT_ENTERED;
                                    }
                                    /**
                                     * @dev Prevents a contract from calling itself, directly or indirectly.
                                     * Calling a `nonReentrant` function from another `nonReentrant`
                                     * function is not supported. It is possible to prevent this from happening
                                     * by making the `nonReentrant` function external, and make it call a
                                     * `private` function that does the actual work.
                                     */
                                    modifier nonReentrant() {
                                        // On the first call to nonReentrant, _notEntered will be true
                                        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
                                        // Any calls to nonReentrant after this point will fail
                                        _status = _ENTERED;
                                        _;
                                        // By storing the original value once again, a refund is triggered (see
                                        // https://eips.ethereum.org/EIPS/eip-2200)
                                        _status = _NOT_ENTERED;
                                    }
                                }
                                // 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";
                                import "../../../utils/Address.sol";
                                /**
                                 * @title SafeERC20
                                 * @dev Wrappers around ERC20 operations that throw on failure (when the token
                                 * contract returns false). Tokens that return no value (and instead revert or
                                 * throw on failure) are also supported, non-reverting calls are assumed to be
                                 * successful.
                                 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
                                 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
                                 */
                                library SafeERC20 {
                                    using Address for address;
                                    function safeTransfer(
                                        IERC20 token,
                                        address to,
                                        uint256 value
                                    ) internal {
                                        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
                                    }
                                    function safeTransferFrom(
                                        IERC20 token,
                                        address from,
                                        address to,
                                        uint256 value
                                    ) internal {
                                        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
                                    }
                                    /**
                                     * @dev Deprecated. This function has issues similar to the ones found in
                                     * {IERC20-approve}, and its usage is discouraged.
                                     *
                                     * Whenever possible, use {safeIncreaseAllowance} and
                                     * {safeDecreaseAllowance} instead.
                                     */
                                    function safeApprove(
                                        IERC20 token,
                                        address spender,
                                        uint256 value
                                    ) internal {
                                        // safeApprove should only be called when setting an initial allowance,
                                        // or when resetting it to zero. To increase and decrease it, use
                                        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
                                        require(
                                            (value == 0) || (token.allowance(address(this), spender) == 0),
                                            "SafeERC20: approve from non-zero to non-zero allowance"
                                        );
                                        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
                                    }
                                    function safeIncreaseAllowance(
                                        IERC20 token,
                                        address spender,
                                        uint256 value
                                    ) internal {
                                        uint256 newAllowance = token.allowance(address(this), spender) + value;
                                        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
                                    }
                                    function safeDecreaseAllowance(
                                        IERC20 token,
                                        address spender,
                                        uint256 value
                                    ) internal {
                                        unchecked {
                                            uint256 oldAllowance = token.allowance(address(this), spender);
                                            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
                                            uint256 newAllowance = oldAllowance - value;
                                            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
                                        }
                                    }
                                    /**
                                     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
                                     * on the return value: the return value is optional (but if data is returned, it must not be false).
                                     * @param token The token targeted by the call.
                                     * @param data The call data (encoded using abi.encode or one of its variants).
                                     */
                                    function _callOptionalReturn(IERC20 token, bytes memory data) private {
                                        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
                                        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
                                        // the target address contains contract code and also asserts for success in the low-level call.
                                        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
                                        if (returndata.length > 0) {
                                            // Return data is optional
                                            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
                                        }
                                    }
                                }
                                // SPDX-License-Identifier: MIT
                                pragma solidity ^0.8.0;
                                /**
                                 * @dev Collection of functions related to the address type
                                 */
                                library Address {
                                    /**
                                     * @dev Returns true if `account` is a contract.
                                     *
                                     * [IMPORTANT]
                                     * ====
                                     * It is unsafe to assume that an address for which this function returns
                                     * false is an externally-owned account (EOA) and not a contract.
                                     *
                                     * Among others, `isContract` will return false for the following
                                     * types of addresses:
                                     *
                                     *  - an externally-owned account
                                     *  - a contract in construction
                                     *  - an address where a contract will be created
                                     *  - an address where a contract lived, but was destroyed
                                     * ====
                                     */
                                    function isContract(address account) internal view returns (bool) {
                                        // This method relies on extcodesize, which returns 0 for contracts in
                                        // construction, since the code is only stored at the end of the
                                        // constructor execution.
                                        uint256 size;
                                        assembly {
                                            size := extcodesize(account)
                                        }
                                        return size > 0;
                                    }
                                    /**
                                     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
                                     * `recipient`, forwarding all available gas and reverting on errors.
                                     *
                                     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
                                     * of certain opcodes, possibly making contracts go over the 2300 gas limit
                                     * imposed by `transfer`, making them unable to receive funds via
                                     * `transfer`. {sendValue} removes this limitation.
                                     *
                                     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
                                     *
                                     * IMPORTANT: because control is transferred to `recipient`, care must be
                                     * taken to not create reentrancy vulnerabilities. Consider using
                                     * {ReentrancyGuard} or the
                                     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
                                     */
                                    function sendValue(address payable recipient, uint256 amount) internal {
                                        require(address(this).balance >= amount, "Address: insufficient balance");
                                        (bool success, ) = recipient.call{value: amount}("");
                                        require(success, "Address: unable to send value, recipient may have reverted");
                                    }
                                    /**
                                     * @dev Performs a Solidity function call using a low level `call`. A
                                     * plain `call` is an unsafe replacement for a function call: use this
                                     * function instead.
                                     *
                                     * If `target` reverts with a revert reason, it is bubbled up by this
                                     * function (like regular Solidity function calls).
                                     *
                                     * Returns the raw returned data. To convert to the expected return value,
                                     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
                                     *
                                     * Requirements:
                                     *
                                     * - `target` must be a contract.
                                     * - calling `target` with `data` must not revert.
                                     *
                                     * _Available since v3.1._
                                     */
                                    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
                                        return functionCall(target, data, "Address: low-level call failed");
                                    }
                                    /**
                                     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
                                     * `errorMessage` as a fallback revert reason when `target` reverts.
                                     *
                                     * _Available since v3.1._
                                     */
                                    function functionCall(
                                        address target,
                                        bytes memory data,
                                        string memory errorMessage
                                    ) internal returns (bytes memory) {
                                        return functionCallWithValue(target, data, 0, errorMessage);
                                    }
                                    /**
                                     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                                     * but also transferring `value` wei to `target`.
                                     *
                                     * Requirements:
                                     *
                                     * - the calling contract must have an ETH balance of at least `value`.
                                     * - the called Solidity function must be `payable`.
                                     *
                                     * _Available since v3.1._
                                     */
                                    function functionCallWithValue(
                                        address target,
                                        bytes memory data,
                                        uint256 value
                                    ) internal returns (bytes memory) {
                                        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
                                    }
                                    /**
                                     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
                                     * with `errorMessage` as a fallback revert reason when `target` reverts.
                                     *
                                     * _Available since v3.1._
                                     */
                                    function functionCallWithValue(
                                        address target,
                                        bytes memory data,
                                        uint256 value,
                                        string memory errorMessage
                                    ) internal returns (bytes memory) {
                                        require(address(this).balance >= value, "Address: insufficient balance for call");
                                        require(isContract(target), "Address: call to non-contract");
                                        (bool success, bytes memory returndata) = target.call{value: value}(data);
                                        return verifyCallResult(success, returndata, errorMessage);
                                    }
                                    /**
                                     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                                     * but performing a static call.
                                     *
                                     * _Available since v3.3._
                                     */
                                    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                                        return functionStaticCall(target, data, "Address: low-level static call failed");
                                    }
                                    /**
                                     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                                     * but performing a static call.
                                     *
                                     * _Available since v3.3._
                                     */
                                    function functionStaticCall(
                                        address target,
                                        bytes memory data,
                                        string memory errorMessage
                                    ) internal view returns (bytes memory) {
                                        require(isContract(target), "Address: static call to non-contract");
                                        (bool success, bytes memory returndata) = target.staticcall(data);
                                        return verifyCallResult(success, returndata, errorMessage);
                                    }
                                    /**
                                     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                                     * but performing a delegate call.
                                     *
                                     * _Available since v3.4._
                                     */
                                    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
                                        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
                                    }
                                    /**
                                     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                                     * but performing a delegate call.
                                     *
                                     * _Available since v3.4._
                                     */
                                    function functionDelegateCall(
                                        address target,
                                        bytes memory data,
                                        string memory errorMessage
                                    ) internal returns (bytes memory) {
                                        require(isContract(target), "Address: delegate call to non-contract");
                                        (bool success, bytes memory returndata) = target.delegatecall(data);
                                        return verifyCallResult(success, returndata, errorMessage);
                                    }
                                    /**
                                     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
                                     * revert reason using the provided one.
                                     *
                                     * _Available since v4.3._
                                     */
                                    function verifyCallResult(
                                        bool success,
                                        bytes memory returndata,
                                        string memory errorMessage
                                    ) internal pure returns (bytes memory) {
                                        if (success) {
                                            return returndata;
                                        } else {
                                            // Look for revert reason and bubble it up if present
                                            if (returndata.length > 0) {
                                                // The easiest way to bubble the revert reason is using memory via assembly
                                                assembly {
                                                    let returndata_size := mload(returndata)
                                                    revert(add(32, returndata), returndata_size)
                                                }
                                            } else {
                                                revert(errorMessage);
                                            }
                                        }
                                    }
                                }
                                // 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 Library for reading and writing primitive types to specific storage slots.
                                 *
                                 * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
                                 * This library helps with reading and writing to such slots without the need for inline assembly.
                                 *
                                 * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
                                 *
                                 * Example usage to set ERC1967 implementation slot:
                                 * ```
                                 * contract ERC1967 {
                                 *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
                                 *
                                 *     function _getImplementation() internal view returns (address) {
                                 *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
                                 *     }
                                 *
                                 *     function _setImplementation(address newImplementation) internal {
                                 *         require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
                                 *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
                                 *     }
                                 * }
                                 * ```
                                 *
                                 * _Available since v4.1 for `address`, `bool`, `bytes32`, and `uint256`._
                                 */
                                library StorageSlot {
                                    struct AddressSlot {
                                        address value;
                                    }
                                    struct BooleanSlot {
                                        bool value;
                                    }
                                    struct Bytes32Slot {
                                        bytes32 value;
                                    }
                                    struct Uint256Slot {
                                        uint256 value;
                                    }
                                    /**
                                     * @dev Returns an `AddressSlot` with member `value` located at `slot`.
                                     */
                                    function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
                                        assembly {
                                            r.slot := slot
                                        }
                                    }
                                    /**
                                     * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
                                     */
                                    function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
                                        assembly {
                                            r.slot := slot
                                        }
                                    }
                                    /**
                                     * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
                                     */
                                    function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
                                        assembly {
                                            r.slot := slot
                                        }
                                    }
                                    /**
                                     * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
                                     */
                                    function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
                                        assembly {
                                            r.slot := slot
                                        }
                                    }
                                }
                                // contracts/Structs.sol
                                // SPDX-License-Identifier: Apache 2
                                pragma solidity ^0.8.0;
                                interface Structs {
                                \tstruct Provider {
                                \t\tuint16 chainId;
                                \t\tuint16 governanceChainId;
                                \t\tbytes32 governanceContract;
                                \t}
                                \tstruct GuardianSet {
                                \t\taddress[] keys;
                                \t\tuint32 expirationTime;
                                \t}
                                \tstruct Signature {
                                \t\tbytes32 r;
                                \t\tbytes32 s;
                                \t\tuint8 v;
                                \t\tuint8 guardianIndex;
                                \t}
                                \tstruct VM {
                                \t\tuint8 version;
                                \t\tuint32 timestamp;
                                \t\tuint32 nonce;
                                \t\tuint16 emitterChainId;
                                \t\tbytes32 emitterAddress;
                                \t\tuint64 sequence;
                                \t\tuint8 consistencyLevel;
                                \t\tbytes payload;
                                \t\tuint32 guardianSetIndex;
                                \t\tSignature[] signatures;
                                \t\tbytes32 hash;
                                \t}
                                }
                                // contracts/Bridge.sol
                                // SPDX-License-Identifier: Apache 2
                                pragma solidity ^0.8.0;
                                import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
                                import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
                                import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
                                import "../libraries/external/BytesLib.sol";
                                import "./BridgeGetters.sol";
                                import "./BridgeSetters.sol";
                                import "./BridgeStructs.sol";
                                import "./BridgeGovernance.sol";
                                import "./token/Token.sol";
                                import "./token/TokenImplementation.sol";
                                contract Bridge is BridgeGovernance, ReentrancyGuard {
                                    using BytesLib for bytes;
                                    // Produce a AssetMeta message for a given token
                                    function attestToken(address tokenAddress, uint32 nonce) public payable returns (uint64 sequence){
                                        // decimals, symbol & token are not part of the core ERC20 token standard, so we need to support contracts that dont implement them
                                        (,bytes memory queriedDecimals) = tokenAddress.staticcall(abi.encodeWithSignature("decimals()"));
                                        (,bytes memory queriedSymbol) = tokenAddress.staticcall(abi.encodeWithSignature("symbol()"));
                                        (,bytes memory queriedName) = tokenAddress.staticcall(abi.encodeWithSignature("name()"));
                                        uint8 decimals = abi.decode(queriedDecimals, (uint8));
                                        string memory symbolString = abi.decode(queriedSymbol, (string));
                                        string memory nameString = abi.decode(queriedName, (string));
                                        bytes32 symbol;
                                        bytes32 name;
                                        assembly {
                                            // first 32 bytes hold string length
                                            symbol := mload(add(symbolString, 32))
                                            name := mload(add(nameString, 32))
                                        }
                                        BridgeStructs.AssetMeta memory meta = BridgeStructs.AssetMeta({
                                        payloadID : 2,
                                        // Address of the token. Left-zero-padded if shorter than 32 bytes
                                        tokenAddress : bytes32(uint256(uint160(tokenAddress))),
                                        // Chain ID of the token
                                        tokenChain : chainId(),
                                        // Number of decimals of the token (big-endian uint8)
                                        decimals : decimals,
                                        // Symbol of the token (UTF-8)
                                        symbol : symbol,
                                        // Name of the token (UTF-8)
                                        name : name
                                        });
                                        bytes memory encoded = encodeAssetMeta(meta);
                                        sequence = wormhole().publishMessage{
                                            value : msg.value
                                        }(nonce, encoded, 15);
                                    }
                                    function wrapAndTransferETH(uint16 recipientChain, bytes32 recipient, uint256 arbiterFee, uint32 nonce) public payable returns (uint64 sequence) {
                                        uint wormholeFee = wormhole().messageFee();
                                        require(wormholeFee < msg.value, "value is smaller than wormhole fee");
                                        uint amount = msg.value - wormholeFee;
                                        require(arbiterFee <= amount, "fee is bigger than amount minus wormhole fee");
                                        uint normalizedAmount = normalizeAmount(amount, 18);
                                        uint normalizedArbiterFee = normalizeAmount(arbiterFee, 18);
                                        // refund dust
                                        uint dust = amount - deNormalizeAmount(normalizedAmount, 18);
                                        if (dust > 0) {
                                            payable(msg.sender).transfer(dust);
                                        }
                                        // deposit into WETH
                                        WETH().deposit{
                                            value : amount - dust
                                        }();
                                        // track and check outstanding token amounts
                                        bridgeOut(address(WETH()), normalizedAmount);
                                        sequence = logTransfer(chainId(), bytes32(uint256(uint160(address(WETH())))), normalizedAmount, recipientChain, recipient, normalizedArbiterFee, wormholeFee, nonce);
                                    }
                                    // Initiate a Transfer
                                    function transferTokens(address token, uint256 amount, uint16 recipientChain, bytes32 recipient, uint256 arbiterFee, uint32 nonce) public payable nonReentrant returns (uint64 sequence) {
                                        // determine token parameters
                                        uint16 tokenChain;
                                        bytes32 tokenAddress;
                                        if (isWrappedAsset(token)) {
                                            tokenChain = TokenImplementation(token).chainId();
                                            tokenAddress = TokenImplementation(token).nativeContract();
                                        } else {
                                            tokenChain = chainId();
                                            tokenAddress = bytes32(uint256(uint160(token)));
                                        }
                                        // query tokens decimals
                                        (,bytes memory queriedDecimals) = token.staticcall(abi.encodeWithSignature("decimals()"));
                                        uint8 decimals = abi.decode(queriedDecimals, (uint8));
                                        // don't deposit dust that can not be bridged due to the decimal shift
                                        amount = deNormalizeAmount(normalizeAmount(amount, decimals), decimals);
                                        if (tokenChain == chainId()) {
                                            // query own token balance before transfer
                                            (,bytes memory queriedBalanceBefore) = token.staticcall(abi.encodeWithSelector(IERC20.balanceOf.selector, address(this)));
                                            uint256 balanceBefore = abi.decode(queriedBalanceBefore, (uint256));
                                            // transfer tokens
                                            SafeERC20.safeTransferFrom(IERC20(token), msg.sender, address(this), amount);
                                            // query own token balance after transfer
                                            (,bytes memory queriedBalanceAfter) = token.staticcall(abi.encodeWithSelector(IERC20.balanceOf.selector, address(this)));
                                            uint256 balanceAfter = abi.decode(queriedBalanceAfter, (uint256));
                                            // correct amount for potential transfer fees
                                            amount = balanceAfter - balanceBefore;
                                        } else {
                                            SafeERC20.safeTransferFrom(IERC20(token), msg.sender, address(this), amount);
                                            TokenImplementation(token).burn(address(this), amount);
                                        }
                                        // normalize amounts decimals
                                        uint256 normalizedAmount = normalizeAmount(amount, decimals);
                                        uint256 normalizedArbiterFee = normalizeAmount(arbiterFee, decimals);
                                        // track and check outstanding token amounts
                                        if (tokenChain == chainId()) {
                                            bridgeOut(token, normalizedAmount);
                                        }
                                        sequence = logTransfer(tokenChain, tokenAddress, normalizedAmount, recipientChain, recipient, normalizedArbiterFee, msg.value, nonce);
                                    }
                                    function normalizeAmount(uint256 amount, uint8 decimals) internal pure returns(uint256){
                                        if (decimals > 8) {
                                            amount /= 10 ** (decimals - 8);
                                        }
                                        return amount;
                                    }
                                    function deNormalizeAmount(uint256 amount, uint8 decimals) internal pure returns(uint256){
                                        if (decimals > 8) {
                                            amount *= 10 ** (decimals - 8);
                                        }
                                        return amount;
                                    }
                                    function logTransfer(uint16 tokenChain, bytes32 tokenAddress, uint256 amount, uint16 recipientChain, bytes32 recipient, uint256 fee, uint256 callValue, uint32 nonce) internal returns (uint64 sequence) {
                                        require(fee <= amount, "fee exceeds amount");
                                        BridgeStructs.Transfer memory transfer = BridgeStructs.Transfer({
                                            payloadID : 1,
                                            amount : amount,
                                            tokenAddress : tokenAddress,
                                            tokenChain : tokenChain,
                                            to : recipient,
                                            toChain : recipientChain,
                                            fee : fee
                                        });
                                        bytes memory encoded = encodeTransfer(transfer);
                                        sequence = wormhole().publishMessage{
                                            value : callValue
                                        }(nonce, encoded, 15);
                                    }
                                    function updateWrapped(bytes memory encodedVm) external returns (address token) {
                                        (IWormhole.VM memory vm, bool valid, string memory reason) = wormhole().parseAndVerifyVM(encodedVm);
                                        require(valid, reason);
                                        require(verifyBridgeVM(vm), "invalid emitter");
                                        BridgeStructs.AssetMeta memory meta = parseAssetMeta(vm.payload);
                                        return _updateWrapped(meta, vm.sequence);
                                    }
                                    function _updateWrapped(BridgeStructs.AssetMeta memory meta, uint64 sequence) internal returns (address token) {
                                        address wrapped = wrappedAsset(meta.tokenChain, meta.tokenAddress);
                                        require(wrapped != address(0), "wrapped asset does not exists");
                                        // Update metadata
                                        TokenImplementation(wrapped).updateDetails(bytes32ToString(meta.name), bytes32ToString(meta.symbol), sequence);
                                        return wrapped;
                                    }
                                    function createWrapped(bytes memory encodedVm) external returns (address token) {
                                        (IWormhole.VM memory vm, bool valid, string memory reason) = wormhole().parseAndVerifyVM(encodedVm);
                                        require(valid, reason);
                                        require(verifyBridgeVM(vm), "invalid emitter");
                                        BridgeStructs.AssetMeta memory meta = parseAssetMeta(vm.payload);
                                        return _createWrapped(meta, vm.sequence);
                                    }
                                    // Creates a wrapped asset using AssetMeta
                                    function _createWrapped(BridgeStructs.AssetMeta memory meta, uint64 sequence) internal returns (address token) {
                                        require(meta.tokenChain != chainId(), "can only wrap tokens from foreign chains");
                                        require(wrappedAsset(meta.tokenChain, meta.tokenAddress) == address(0), "wrapped asset already exists");
                                        // initialize the TokenImplementation
                                        bytes memory initialisationArgs = abi.encodeWithSelector(
                                            TokenImplementation.initialize.selector,
                                            bytes32ToString(meta.name),
                                            bytes32ToString(meta.symbol),
                                            meta.decimals,
                                            sequence,
                                            address(this),
                                            meta.tokenChain,
                                            meta.tokenAddress
                                        );
                                        // initialize the BeaconProxy
                                        bytes memory constructorArgs = abi.encode(address(this), initialisationArgs);
                                        // deployment code
                                        bytes memory bytecode = abi.encodePacked(type(BridgeToken).creationCode, constructorArgs);
                                        bytes32 salt = keccak256(abi.encodePacked(meta.tokenChain, meta.tokenAddress));
                                        assembly {
                                            token := create2(0, add(bytecode, 0x20), mload(bytecode), salt)
                                            if iszero(extcodesize(token)) {
                                                revert(0, 0)
                                            }
                                        }
                                        setWrappedAsset(meta.tokenChain, meta.tokenAddress, token);
                                    }
                                    function completeTransfer(bytes memory encodedVm) public {
                                        _completeTransfer(encodedVm, false);
                                    }
                                    function completeTransferAndUnwrapETH(bytes memory encodedVm) public {
                                        _completeTransfer(encodedVm, true);
                                    }
                                    // Execute a Transfer message
                                    function _completeTransfer(bytes memory encodedVm, bool unwrapWETH) internal {
                                        (IWormhole.VM memory vm, bool valid, string memory reason) = wormhole().parseAndVerifyVM(encodedVm);
                                        require(valid, reason);
                                        require(verifyBridgeVM(vm), "invalid emitter");
                                        BridgeStructs.Transfer memory transfer = parseTransfer(vm.payload);
                                        require(!isTransferCompleted(vm.hash), "transfer already completed");
                                        setTransferCompleted(vm.hash);
                                        require(transfer.toChain == chainId(), "invalid target chain");
                                        IERC20 transferToken;
                                        if (transfer.tokenChain == chainId()) {
                                            transferToken = IERC20(address(uint160(uint256(transfer.tokenAddress))));
                                            // track outstanding token amounts
                                            bridgedIn(address(transferToken), transfer.amount);
                                        } else {
                                            address wrapped = wrappedAsset(transfer.tokenChain, transfer.tokenAddress);
                                            require(wrapped != address(0), "no wrapper for this token created yet");
                                            transferToken = IERC20(wrapped);
                                        }
                                        require(unwrapWETH == false || address(transferToken) == address(WETH()), "invalid token, can only unwrap WETH");
                                        // query decimals
                                        (,bytes memory queriedDecimals) = address(transferToken).staticcall(abi.encodeWithSignature("decimals()"));
                                        uint8 decimals = abi.decode(queriedDecimals, (uint8));
                                        // adjust decimals
                                        uint256 nativeAmount = deNormalizeAmount(transfer.amount, decimals);
                                        uint256 nativeFee = deNormalizeAmount(transfer.fee, decimals);
                                        // transfer fee to arbiter
                                        if (nativeFee > 0) {
                                            require(nativeFee <= nativeAmount, "fee higher than transferred amount");
                                            if (unwrapWETH) {
                                                WETH().withdraw(nativeFee);
                                                payable(msg.sender).transfer(nativeFee);
                                            } else {
                                                if (transfer.tokenChain != chainId()) {
                                                    // mint wrapped asset
                                                    TokenImplementation(address(transferToken)).mint(msg.sender, nativeFee);
                                                } else {
                                                    SafeERC20.safeTransfer(transferToken, msg.sender, nativeFee);
                                                }
                                            }
                                        }
                                        // transfer bridged amount to recipient
                                        uint transferAmount = nativeAmount - nativeFee;
                                        address transferRecipient = address(uint160(uint256(transfer.to)));
                                        if (unwrapWETH) {
                                            WETH().withdraw(transferAmount);
                                            payable(transferRecipient).transfer(transferAmount);
                                        } else {
                                            if (transfer.tokenChain != chainId()) {
                                                // mint wrapped asset
                                                TokenImplementation(address(transferToken)).mint(transferRecipient, transferAmount);
                                            } else {
                                                SafeERC20.safeTransfer(transferToken, transferRecipient, transferAmount);
                                            }
                                        }
                                    }
                                    function bridgeOut(address token, uint normalizedAmount) internal {
                                        uint outstanding = outstandingBridged(token);
                                        require(outstanding + normalizedAmount <= type(uint64).max, "transfer exceeds max outstanding bridged token amount");
                                        setOutstandingBridged(token, outstanding + normalizedAmount);
                                    }
                                    function bridgedIn(address token, uint normalizedAmount) internal {
                                        setOutstandingBridged(token, outstandingBridged(token) - normalizedAmount);
                                    }
                                    function verifyBridgeVM(IWormhole.VM memory vm) internal view returns (bool){
                                        if (bridgeContracts(vm.emitterChainId) == vm.emitterAddress) {
                                            return true;
                                        }
                                        return false;
                                    }
                                    function encodeAssetMeta(BridgeStructs.AssetMeta memory meta) public pure returns (bytes memory encoded) {
                                        encoded = abi.encodePacked(
                                            meta.payloadID,
                                            meta.tokenAddress,
                                            meta.tokenChain,
                                            meta.decimals,
                                            meta.symbol,
                                            meta.name
                                        );
                                    }
                                    function encodeTransfer(BridgeStructs.Transfer memory transfer) public pure returns (bytes memory encoded) {
                                        encoded = abi.encodePacked(
                                            transfer.payloadID,
                                            transfer.amount,
                                            transfer.tokenAddress,
                                            transfer.tokenChain,
                                            transfer.to,
                                            transfer.toChain,
                                            transfer.fee
                                        );
                                    }
                                    function parseAssetMeta(bytes memory encoded) public pure returns (BridgeStructs.AssetMeta memory meta) {
                                        uint index = 0;
                                        meta.payloadID = encoded.toUint8(index);
                                        index += 1;
                                        require(meta.payloadID == 2, "invalid AssetMeta");
                                        meta.tokenAddress = encoded.toBytes32(index);
                                        index += 32;
                                        meta.tokenChain = encoded.toUint16(index);
                                        index += 2;
                                        meta.decimals = encoded.toUint8(index);
                                        index += 1;
                                        meta.symbol = encoded.toBytes32(index);
                                        index += 32;
                                        meta.name = encoded.toBytes32(index);
                                        index += 32;
                                        require(encoded.length == index, "invalid AssetMeta");
                                    }
                                    function parseTransfer(bytes memory encoded) public pure returns (BridgeStructs.Transfer memory transfer) {
                                        uint index = 0;
                                        transfer.payloadID = encoded.toUint8(index);
                                        index += 1;
                                        require(transfer.payloadID == 1, "invalid Transfer");
                                        transfer.amount = encoded.toUint256(index);
                                        index += 32;
                                        transfer.tokenAddress = encoded.toBytes32(index);
                                        index += 32;
                                        transfer.tokenChain = encoded.toUint16(index);
                                        index += 2;
                                        transfer.to = encoded.toBytes32(index);
                                        index += 32;
                                        transfer.toChain = encoded.toUint16(index);
                                        index += 2;
                                        transfer.fee = encoded.toUint256(index);
                                        index += 32;
                                        require(encoded.length == index, "invalid Transfer");
                                    }
                                    function bytes32ToString(bytes32 input) internal pure returns (string memory) {
                                        uint256 i;
                                        while (i < 32 && input[i] != 0) {
                                            i++;
                                        }
                                        bytes memory array = new bytes(i);
                                        for (uint c = 0; c < i; c++) {
                                            array[c] = input[c];
                                        }
                                        return string(array);
                                    }
                                    // we need to accept ETH sends to unwrap WETH
                                    receive() external payable {}
                                }// contracts/Getters.sol
                                // SPDX-License-Identifier: Apache 2
                                pragma solidity ^0.8.0;
                                import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
                                import "../interfaces/IWormhole.sol";
                                import "./BridgeState.sol";
                                contract BridgeGetters is BridgeState {
                                    function governanceActionIsConsumed(bytes32 hash) public view returns (bool) {
                                        return _state.consumedGovernanceActions[hash];
                                    }
                                    function isInitialized(address impl) public view returns (bool) {
                                        return _state.initializedImplementations[impl];
                                    }
                                    function isTransferCompleted(bytes32 hash) public view returns (bool) {
                                        return _state.completedTransfers[hash];
                                    }
                                    function wormhole() public view returns (IWormhole) {
                                        return IWormhole(_state.wormhole);
                                    }
                                    function chainId() public view returns (uint16){
                                        return _state.provider.chainId;
                                    }
                                    function governanceChainId() public view returns (uint16){
                                        return _state.provider.governanceChainId;
                                    }
                                    function governanceContract() public view returns (bytes32){
                                        return _state.provider.governanceContract;
                                    }
                                    function wrappedAsset(uint16 tokenChainId, bytes32 tokenAddress) public view returns (address){
                                        return _state.wrappedAssets[tokenChainId][tokenAddress];
                                    }
                                    function bridgeContracts(uint16 chainId_) public view returns (bytes32){
                                        return _state.bridgeImplementations[chainId_];
                                    }
                                    function tokenImplementation() public view returns (address){
                                        return _state.tokenImplementation;
                                    }
                                    function WETH() public view returns (IWETH){
                                        return IWETH(_state.provider.WETH);
                                    }
                                    function outstandingBridged(address token) public view returns (uint256){
                                        return _state.outstandingBridged[token];
                                    }
                                    function isWrappedAsset(address token) public view returns (bool){
                                        return _state.isWrappedAsset[token];
                                    }
                                }
                                interface IWETH is IERC20 {
                                    function deposit() external payable;
                                    function withdraw(uint amount) external;
                                }// contracts/Bridge.sol
                                // SPDX-License-Identifier: Apache 2
                                pragma solidity ^0.8.0;
                                import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
                                import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
                                import "@openzeppelin/contracts/proxy/ERC1967/ERC1967Upgrade.sol";
                                import "../libraries/external/BytesLib.sol";
                                import "./BridgeGetters.sol";
                                import "./BridgeSetters.sol";
                                import "./BridgeStructs.sol";
                                import "./token/Token.sol";
                                import "./token/TokenImplementation.sol";
                                import "../interfaces/IWormhole.sol";
                                contract BridgeGovernance is BridgeGetters, BridgeSetters, ERC1967Upgrade {
                                    using BytesLib for bytes;
                                    // "TokenBridge" (left padded)
                                    bytes32 constant module = 0x000000000000000000000000000000000000000000546f6b656e427269646765;
                                    // Execute a RegisterChain governance message
                                    function registerChain(bytes memory encodedVM) public {
                                        (IWormhole.VM memory vm, bool valid, string memory reason) = verifyGovernanceVM(encodedVM);
                                        require(valid, reason);
                                        setGovernanceActionConsumed(vm.hash);
                                        BridgeStructs.RegisterChain memory chain = parseRegisterChain(vm.payload);
                                        require(chain.chainId == chainId() || chain.chainId == 0, "invalid chain id");
                                        require(bridgeContracts(chain.emitterChainID) == bytes32(0), "chain already registered");
                                        setBridgeImplementation(chain.emitterChainID, chain.emitterAddress);
                                    }
                                    // Execute a UpgradeContract governance message
                                    function upgrade(bytes memory encodedVM) public {
                                        (IWormhole.VM memory vm, bool valid, string memory reason) = verifyGovernanceVM(encodedVM);
                                        require(valid, reason);
                                        setGovernanceActionConsumed(vm.hash);
                                        BridgeStructs.UpgradeContract memory implementation = parseUpgrade(vm.payload);
                                        require(implementation.chainId == chainId(), "wrong chain id");
                                        upgradeImplementation(address(uint160(uint256(implementation.newContract))));
                                    }
                                    function verifyGovernanceVM(bytes memory encodedVM) internal view returns (IWormhole.VM memory parsedVM, bool isValid, string memory invalidReason){
                                        (IWormhole.VM memory vm, bool valid, string memory reason) = wormhole().parseAndVerifyVM(encodedVM);
                                        if (!valid) {
                                            return (vm, valid, reason);
                                        }
                                        if (vm.emitterChainId != governanceChainId()) {
                                            return (vm, false, "wrong governance chain");
                                        }
                                        if (vm.emitterAddress != governanceContract()) {
                                            return (vm, false, "wrong governance contract");
                                        }
                                        if (governanceActionIsConsumed(vm.hash)) {
                                            return (vm, false, "governance action already consumed");
                                        }
                                        return (vm, true, "");
                                    }
                                    event ContractUpgraded(address indexed oldContract, address indexed newContract);
                                    function upgradeImplementation(address newImplementation) internal {
                                        address currentImplementation = _getImplementation();
                                        _upgradeTo(newImplementation);
                                        // Call initialize function of the new implementation
                                        (bool success, bytes memory reason) = newImplementation.delegatecall(abi.encodeWithSignature("initialize()"));
                                        require(success, string(reason));
                                        emit ContractUpgraded(currentImplementation, newImplementation);
                                    }
                                    function parseRegisterChain(bytes memory encoded) public pure returns (BridgeStructs.RegisterChain memory chain) {
                                        uint index = 0;
                                        // governance header
                                        chain.module = encoded.toBytes32(index);
                                        index += 32;
                                        require(chain.module == module, "invalid RegisterChain: wrong module");
                                        chain.action = encoded.toUint8(index);
                                        index += 1;
                                        require(chain.action == 1, "invalid RegisterChain: wrong action");
                                        chain.chainId = encoded.toUint16(index);
                                        index += 2;
                                        // payload
                                        chain.emitterChainID = encoded.toUint16(index);
                                        index += 2;
                                        chain.emitterAddress = encoded.toBytes32(index);
                                        index += 32;
                                        require(encoded.length == index, "invalid RegisterChain: wrong length");
                                    }
                                    function parseUpgrade(bytes memory encoded) public pure returns (BridgeStructs.UpgradeContract memory chain) {
                                        uint index = 0;
                                        // governance header
                                        chain.module = encoded.toBytes32(index);
                                        index += 32;
                                        require(chain.module == module, "invalid UpgradeContract: wrong module");
                                        chain.action = encoded.toUint8(index);
                                        index += 1;
                                        require(chain.action == 2, "invalid UpgradeContract: wrong action");
                                        chain.chainId = encoded.toUint16(index);
                                        index += 2;
                                        // payload
                                        chain.newContract = encoded.toBytes32(index);
                                        index += 32;
                                        require(encoded.length == index, "invalid UpgradeContract: wrong length");
                                    }
                                }
                                // contracts/Implementation.sol
                                // SPDX-License-Identifier: Apache 2
                                pragma solidity ^0.8.0;
                                pragma experimental ABIEncoderV2;
                                import "@openzeppelin/contracts/proxy/ERC1967/ERC1967Upgrade.sol";
                                import "./Bridge.sol";
                                contract BridgeImplementation is Bridge {
                                    // Beacon getter for the token contracts
                                    function implementation() public view returns (address) {
                                        return tokenImplementation();
                                    }
                                    function initialize() initializer public virtual {
                                        // this function needs to be exposed for an upgrade to pass
                                    }
                                    modifier initializer() {
                                        address impl = ERC1967Upgrade._getImplementation();
                                        require(
                                            !isInitialized(impl),
                                            "already initialized"
                                        );
                                        setInitialized(impl);
                                        _;
                                    }
                                }
                                // contracts/Setters.sol
                                // SPDX-License-Identifier: Apache 2
                                pragma solidity ^0.8.0;
                                import "./BridgeState.sol";
                                contract BridgeSetters is BridgeState {
                                    function setInitialized(address implementatiom) internal {
                                        _state.initializedImplementations[implementatiom] = true;
                                    }
                                    function setGovernanceActionConsumed(bytes32 hash) internal {
                                        _state.consumedGovernanceActions[hash] = true;
                                    }
                                    function setTransferCompleted(bytes32 hash) internal {
                                        _state.completedTransfers[hash] = true;
                                    }
                                    function setChainId(uint16 chainId) internal {
                                        _state.provider.chainId = chainId;
                                    }
                                    function setGovernanceChainId(uint16 chainId) internal {
                                        _state.provider.governanceChainId = chainId;
                                    }
                                    function setGovernanceContract(bytes32 governanceContract) internal {
                                        _state.provider.governanceContract = governanceContract;
                                    }
                                    function setBridgeImplementation(uint16 chainId, bytes32 bridgeContract) internal {
                                        _state.bridgeImplementations[chainId] = bridgeContract;
                                    }
                                    function setTokenImplementation(address impl) internal {
                                        _state.tokenImplementation = impl;
                                    }
                                    function setWETH(address weth) internal {
                                        _state.provider.WETH = weth;
                                    }
                                    function setWormhole(address wh) internal {
                                        _state.wormhole = payable(wh);
                                    }
                                    function setWrappedAsset(uint16 tokenChainId, bytes32 tokenAddress, address wrapper) internal {
                                        _state.wrappedAssets[tokenChainId][tokenAddress] = wrapper;
                                        _state.isWrappedAsset[wrapper] = true;
                                    }
                                    function setOutstandingBridged(address token, uint256 outstanding) internal {
                                        _state.outstandingBridged[token] = outstanding;
                                    }
                                }// contracts/State.sol
                                // SPDX-License-Identifier: Apache 2
                                pragma solidity ^0.8.0;
                                import "./BridgeStructs.sol";
                                contract BridgeStorage {
                                    struct Provider {
                                        uint16 chainId;
                                        uint16 governanceChainId;
                                        bytes32 governanceContract;
                                        address WETH;
                                    }
                                    struct Asset {
                                        uint16 chainId;
                                        bytes32 assetAddress;
                                    }
                                    struct State {
                                        address payable wormhole;
                                        address tokenImplementation;
                                        Provider provider;
                                        // Mapping of consumed governance actions
                                        mapping(bytes32 => bool) consumedGovernanceActions;
                                        // Mapping of consumed token transfers
                                        mapping(bytes32 => bool) completedTransfers;
                                        // Mapping of initialized implementations
                                        mapping(address => bool) initializedImplementations;
                                        // Mapping of wrapped assets (chainID => nativeAddress => wrappedAddress)
                                        mapping(uint16 => mapping(bytes32 => address)) wrappedAssets;
                                        // Mapping to safely identify wrapped assets
                                        mapping(address => bool) isWrappedAsset;
                                        // Mapping of native assets to amount outstanding on other chains
                                        mapping(address => uint256) outstandingBridged;
                                        // Mapping of bridge contracts on other chains
                                        mapping(uint16 => bytes32) bridgeImplementations;
                                    }
                                }
                                contract BridgeState {
                                    BridgeStorage.State _state;
                                }// contracts/Structs.sol
                                // SPDX-License-Identifier: Apache 2
                                pragma solidity ^0.8.0;
                                contract BridgeStructs {
                                    struct Transfer {
                                        // PayloadID uint8 = 1
                                        uint8 payloadID;
                                        // Amount being transferred (big-endian uint256)
                                        uint256 amount;
                                        // Address of the token. Left-zero-padded if shorter than 32 bytes
                                        bytes32 tokenAddress;
                                        // Chain ID of the token
                                        uint16 tokenChain;
                                        // Address of the recipient. Left-zero-padded if shorter than 32 bytes
                                        bytes32 to;
                                        // Chain ID of the recipient
                                        uint16 toChain;
                                        // Amount of tokens (big-endian uint256) that the user is willing to pay as relayer fee. Must be <= Amount.
                                        uint256 fee;
                                    }
                                    struct AssetMeta {
                                        // PayloadID uint8 = 2
                                        uint8 payloadID;
                                        // Address of the token. Left-zero-padded if shorter than 32 bytes
                                        bytes32 tokenAddress;
                                        // Chain ID of the token
                                        uint16 tokenChain;
                                        // Number of decimals of the token (big-endian uint256)
                                        uint8 decimals;
                                        // Symbol of the token (UTF-8)
                                        bytes32 symbol;
                                        // Name of the token (UTF-8)
                                        bytes32 name;
                                    }
                                    struct RegisterChain {
                                        // Governance Header
                                        // module: "TokenBridge" left-padded
                                        bytes32 module;
                                        // governance action: 1
                                        uint8 action;
                                        // governance paket chain id: this or 0
                                        uint16 chainId;
                                        // Chain ID
                                        uint16 emitterChainID;
                                        // Emitter address. Left-zero-padded if shorter than 32 bytes
                                        bytes32 emitterAddress;
                                    }
                                    struct UpgradeContract {
                                        // Governance Header
                                        // module: "TokenBridge" left-padded
                                        bytes32 module;
                                        // governance action: 2
                                        uint8 action;
                                        // governance paket chain id
                                        uint16 chainId;
                                        // Address of the new contract
                                        bytes32 newContract;
                                    }
                                }
                                // contracts/Structs.sol
                                // SPDX-License-Identifier: Apache 2
                                pragma solidity ^0.8.0;
                                import "@openzeppelin/contracts/proxy/beacon/BeaconProxy.sol";
                                contract BridgeToken is BeaconProxy {
                                    constructor(address beacon, bytes memory data) BeaconProxy(beacon, data) {
                                    }
                                }// contracts/TokenImplementation.sol
                                // SPDX-License-Identifier: Apache 2
                                pragma solidity ^0.8.0;
                                import "./TokenState.sol";
                                import "@openzeppelin/contracts/access/Ownable.sol";
                                import "@openzeppelin/contracts/utils/Context.sol";
                                import "@openzeppelin/contracts/proxy/beacon/BeaconProxy.sol";
                                // Based on the OpenZepplin ERC20 implementation, licensed under MIT
                                contract TokenImplementation is TokenState, Context {
                                    event Transfer(address indexed from, address indexed to, uint256 value);
                                    event Approval(address indexed owner, address indexed spender, uint256 value);
                                    function initialize(
                                        string memory name_,
                                        string memory symbol_,
                                        uint8 decimals_,
                                        uint64 sequence_,
                                        address owner_,
                                        uint16 chainId_,
                                        bytes32 nativeContract_
                                    ) initializer public {
                                        _state.name = name_;
                                        _state.symbol = symbol_;
                                        _state.decimals = decimals_;
                                        _state.metaLastUpdatedSequence = sequence_;
                                        _state.owner = owner_;
                                        _state.chainId = chainId_;
                                        _state.nativeContract = nativeContract_;
                                    }
                                    function name() public view returns (string memory) {
                                        return string(abi.encodePacked(_state.name, " (Wormhole)"));
                                    }
                                    function symbol() public view returns (string memory) {
                                        return _state.symbol;
                                    }
                                    function owner() public view returns (address) {
                                        return _state.owner;
                                    }
                                    function decimals() public view returns (uint8) {
                                        return _state.decimals;
                                    }
                                    function totalSupply() public view returns (uint256) {
                                        return _state.totalSupply;
                                    }
                                    function chainId() public view returns (uint16) {
                                        return _state.chainId;
                                    }
                                    function nativeContract() public view returns (bytes32) {
                                        return _state.nativeContract;
                                    }
                                    function balanceOf(address account_) public view returns (uint256) {
                                        return _state.balances[account_];
                                    }
                                    function transfer(address recipient_, uint256 amount_) public returns (bool) {
                                        _transfer(_msgSender(), recipient_, amount_);
                                        return true;
                                    }
                                    function allowance(address owner_, address spender_) public view returns (uint256) {
                                        return _state.allowances[owner_][spender_];
                                    }
                                    function approve(address spender_, uint256 amount_) public returns (bool) {
                                        _approve(_msgSender(), spender_, amount_);
                                        return true;
                                    }
                                    function transferFrom(address sender_, address recipient_, uint256 amount_) public returns (bool) {
                                        _transfer(sender_, recipient_, amount_);
                                        uint256 currentAllowance = _state.allowances[sender_][_msgSender()];
                                        require(currentAllowance >= amount_, "ERC20: transfer amount exceeds allowance");
                                        _approve(sender_, _msgSender(), currentAllowance - amount_);
                                        return true;
                                    }
                                    function increaseAllowance(address spender_, uint256 addedValue_) public returns (bool) {
                                        _approve(_msgSender(), spender_, _state.allowances[_msgSender()][spender_] + addedValue_);
                                        return true;
                                    }
                                    function decreaseAllowance(address spender_, uint256 subtractedValue_) public returns (bool) {
                                        uint256 currentAllowance = _state.allowances[_msgSender()][spender_];
                                        require(currentAllowance >= subtractedValue_, "ERC20: decreased allowance below zero");
                                        _approve(_msgSender(), spender_, currentAllowance - subtractedValue_);
                                        return true;
                                    }
                                    function _transfer(address sender_, address recipient_, uint256 amount_) internal {
                                        require(sender_ != address(0), "ERC20: transfer from the zero address");
                                        require(recipient_ != address(0), "ERC20: transfer to the zero address");
                                        uint256 senderBalance = _state.balances[sender_];
                                        require(senderBalance >= amount_, "ERC20: transfer amount exceeds balance");
                                        _state.balances[sender_] = senderBalance - amount_;
                                        _state.balances[recipient_] += amount_;
                                        emit Transfer(sender_, recipient_, amount_);
                                    }
                                    function mint(address account_, uint256 amount_) public onlyOwner {
                                        _mint(account_, amount_);
                                    }
                                    function _mint(address account_, uint256 amount_) internal {
                                        require(account_ != address(0), "ERC20: mint to the zero address");
                                        _state.totalSupply += amount_;
                                        _state.balances[account_] += amount_;
                                        emit Transfer(address(0), account_, amount_);
                                    }
                                    function burn(address account_, uint256 amount_) public onlyOwner {
                                        _burn(account_, amount_);
                                    }
                                    function _burn(address account_, uint256 amount_) internal {
                                        require(account_ != address(0), "ERC20: burn from the zero address");
                                        uint256 accountBalance = _state.balances[account_];
                                        require(accountBalance >= amount_, "ERC20: burn amount exceeds balance");
                                        _state.balances[account_] = accountBalance - amount_;
                                        _state.totalSupply -= amount_;
                                        emit Transfer(account_, address(0), amount_);
                                    }
                                    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");
                                        _state.allowances[owner_][spender_] = amount_;
                                        emit Approval(owner_, spender_, amount_);
                                    }
                                    function updateDetails(string memory name_, string memory symbol_, uint64 sequence_) public onlyOwner {
                                        require(_state.metaLastUpdatedSequence < sequence_, "current metadata is up to date");
                                        _state.name = name_;
                                        _state.symbol = symbol_;
                                        _state.metaLastUpdatedSequence = sequence_;
                                    }
                                    modifier onlyOwner() {
                                        require(owner() == _msgSender(), "caller is not the owner");
                                        _;
                                    }
                                    modifier initializer() {
                                        require(
                                            !_state.initialized,
                                            "Already initialized"
                                        );
                                        _state.initialized = true;
                                        _;
                                    }
                                }
                                // contracts/State.sol
                                // SPDX-License-Identifier: Apache 2
                                pragma solidity ^0.8.0;
                                contract TokenStorage {
                                    struct State {
                                        string name;
                                        string symbol;
                                        uint64 metaLastUpdatedSequence;
                                        uint256 totalSupply;
                                        uint8 decimals;
                                        mapping(address => uint256) balances;
                                        mapping(address => mapping(address => uint256)) allowances;
                                        address owner;
                                        bool initialized;
                                        uint16 chainId;
                                        bytes32 nativeContract;
                                    }
                                }
                                contract TokenState {
                                    TokenStorage.State _state;
                                }// contracts/Messages.sol
                                // SPDX-License-Identifier: Apache 2
                                pragma solidity ^0.8.0;
                                import "../Structs.sol";
                                interface IWormhole is Structs {
                                    event LogMessagePublished(address indexed sender, uint64 sequence, uint32 nonce, bytes payload, uint8 consistencyLevel);
                                    function publishMessage(
                                        uint32 nonce,
                                        bytes memory payload,
                                        uint8 consistencyLevel
                                    ) external payable returns (uint64 sequence);
                                    function parseAndVerifyVM(bytes calldata encodedVM) external view returns (Structs.VM memory vm, bool valid, string memory reason);
                                    function verifyVM(Structs.VM memory vm) external view returns (bool valid, string memory reason);
                                    function verifySignatures(bytes32 hash, Structs.Signature[] memory signatures, Structs.GuardianSet memory guardianSet) external pure returns (bool valid, string memory reason) ;
                                    function parseVM(bytes memory encodedVM) external pure returns (Structs.VM memory vm);
                                    function getGuardianSet(uint32 index) external view returns (Structs.GuardianSet memory) ;
                                    function getCurrentGuardianSetIndex() external view returns (uint32) ;
                                    function getGuardianSetExpiry() external view returns (uint32) ;
                                    function governanceActionIsConsumed(bytes32 hash) external view returns (bool) ;
                                    function isInitialized(address impl) external view returns (bool) ;
                                    function chainId() external view returns (uint16) ;
                                    function governanceChainId() external view returns (uint16);
                                    function governanceContract() external view returns (bytes32);
                                    function messageFee() external view returns (uint256) ;
                                }
                                // SPDX-License-Identifier: Unlicense
                                /*
                                 * @title Solidity Bytes Arrays Utils
                                 * @author Gonçalo Sá <[email protected]>
                                 *
                                 * @dev Bytes tightly packed arrays utility library for ethereum contracts written in Solidity.
                                 *      The library lets you concatenate, slice and type cast bytes arrays both in memory and storage.
                                 */
                                pragma solidity >=0.8.0 <0.9.0;
                                library BytesLib {
                                    function concat(
                                        bytes memory _preBytes,
                                        bytes memory _postBytes
                                    )
                                        internal
                                        pure
                                        returns (bytes memory)
                                    {
                                        bytes memory tempBytes;
                                        assembly {
                                            // Get a location of some free memory and store it in tempBytes as
                                            // Solidity does for memory variables.
                                            tempBytes := mload(0x40)
                                            // Store the length of the first bytes array at the beginning of
                                            // the memory for tempBytes.
                                            let length := mload(_preBytes)
                                            mstore(tempBytes, length)
                                            // Maintain a memory counter for the current write location in the
                                            // temp bytes array by adding the 32 bytes for the array length to
                                            // the starting location.
                                            let mc := add(tempBytes, 0x20)
                                            // Stop copying when the memory counter reaches the length of the
                                            // first bytes array.
                                            let end := add(mc, length)
                                            for {
                                                // Initialize a copy counter to the start of the _preBytes data,
                                                // 32 bytes into its memory.
                                                let cc := add(_preBytes, 0x20)
                                            } lt(mc, end) {
                                                // Increase both counters by 32 bytes each iteration.
                                                mc := add(mc, 0x20)
                                                cc := add(cc, 0x20)
                                            } {
                                                // Write the _preBytes data into the tempBytes memory 32 bytes
                                                // at a time.
                                                mstore(mc, mload(cc))
                                            }
                                            // Add the length of _postBytes to the current length of tempBytes
                                            // and store it as the new length in the first 32 bytes of the
                                            // tempBytes memory.
                                            length := mload(_postBytes)
                                            mstore(tempBytes, add(length, mload(tempBytes)))
                                            // Move the memory counter back from a multiple of 0x20 to the
                                            // actual end of the _preBytes data.
                                            mc := end
                                            // Stop copying when the memory counter reaches the new combined
                                            // length of the arrays.
                                            end := add(mc, length)
                                            for {
                                                let cc := add(_postBytes, 0x20)
                                            } lt(mc, end) {
                                                mc := add(mc, 0x20)
                                                cc := add(cc, 0x20)
                                            } {
                                                mstore(mc, mload(cc))
                                            }
                                            // Update the free-memory pointer by padding our last write location
                                            // to 32 bytes: add 31 bytes to the end of tempBytes to move to the
                                            // next 32 byte block, then round down to the nearest multiple of
                                            // 32. If the sum of the length of the two arrays is zero then add
                                            // one before rounding down to leave a blank 32 bytes (the length block with 0).
                                            mstore(0x40, and(
                                              add(add(end, iszero(add(length, mload(_preBytes)))), 31),
                                              not(31) // Round down to the nearest 32 bytes.
                                            ))
                                        }
                                        return tempBytes;
                                    }
                                    function concatStorage(bytes storage _preBytes, bytes memory _postBytes) internal {
                                        assembly {
                                            // Read the first 32 bytes of _preBytes storage, which is the length
                                            // of the array. (We don't need to use the offset into the slot
                                            // because arrays use the entire slot.)
                                            let fslot := sload(_preBytes.slot)
                                            // Arrays of 31 bytes or less have an even value in their slot,
                                            // while longer arrays have an odd value. The actual length is
                                            // the slot divided by two for odd values, and the lowest order
                                            // byte divided by two for even values.
                                            // If the slot is even, bitwise and the slot with 255 and divide by
                                            // two to get the length. If the slot is odd, bitwise and the slot
                                            // with -1 and divide by two.
                                            let slength := div(and(fslot, sub(mul(0x100, iszero(and(fslot, 1))), 1)), 2)
                                            let mlength := mload(_postBytes)
                                            let newlength := add(slength, mlength)
                                            // slength can contain both the length and contents of the array
                                            // if length < 32 bytes so let's prepare for that
                                            // v. http://solidity.readthedocs.io/en/latest/miscellaneous.html#layout-of-state-variables-in-storage
                                            switch add(lt(slength, 32), lt(newlength, 32))
                                            case 2 {
                                                // Since the new array still fits in the slot, we just need to
                                                // update the contents of the slot.
                                                // uint256(bytes_storage) = uint256(bytes_storage) + uint256(bytes_memory) + new_length
                                                sstore(
                                                    _preBytes.slot,
                                                    // all the modifications to the slot are inside this
                                                    // next block
                                                    add(
                                                        // we can just add to the slot contents because the
                                                        // bytes we want to change are the LSBs
                                                        fslot,
                                                        add(
                                                            mul(
                                                                div(
                                                                    // load the bytes from memory
                                                                    mload(add(_postBytes, 0x20)),
                                                                    // zero all bytes to the right
                                                                    exp(0x100, sub(32, mlength))
                                                                ),
                                                                // and now shift left the number of bytes to
                                                                // leave space for the length in the slot
                                                                exp(0x100, sub(32, newlength))
                                                            ),
                                                            // increase length by the double of the memory
                                                            // bytes length
                                                            mul(mlength, 2)
                                                        )
                                                    )
                                                )
                                            }
                                            case 1 {
                                                // The stored value fits in the slot, but the combined value
                                                // will exceed it.
                                                // get the keccak hash to get the contents of the array
                                                mstore(0x0, _preBytes.slot)
                                                let sc := add(keccak256(0x0, 0x20), div(slength, 32))
                                                // save new length
                                                sstore(_preBytes.slot, add(mul(newlength, 2), 1))
                                                // The contents of the _postBytes array start 32 bytes into
                                                // the structure. Our first read should obtain the `submod`
                                                // bytes that can fit into the unused space in the last word
                                                // of the stored array. To get this, we read 32 bytes starting
                                                // from `submod`, so the data we read overlaps with the array
                                                // contents by `submod` bytes. Masking the lowest-order
                                                // `submod` bytes allows us to add that value directly to the
                                                // stored value.
                                                let submod := sub(32, slength)
                                                let mc := add(_postBytes, submod)
                                                let end := add(_postBytes, mlength)
                                                let mask := sub(exp(0x100, submod), 1)
                                                sstore(
                                                    sc,
                                                    add(
                                                        and(
                                                            fslot,
                                                            0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff00
                                                        ),
                                                        and(mload(mc), mask)
                                                    )
                                                )
                                                for {
                                                    mc := add(mc, 0x20)
                                                    sc := add(sc, 1)
                                                } lt(mc, end) {
                                                    sc := add(sc, 1)
                                                    mc := add(mc, 0x20)
                                                } {
                                                    sstore(sc, mload(mc))
                                                }
                                                mask := exp(0x100, sub(mc, end))
                                                sstore(sc, mul(div(mload(mc), mask), mask))
                                            }
                                            default {
                                                // get the keccak hash to get the contents of the array
                                                mstore(0x0, _preBytes.slot)
                                                // Start copying to the last used word of the stored array.
                                                let sc := add(keccak256(0x0, 0x20), div(slength, 32))
                                                // save new length
                                                sstore(_preBytes.slot, add(mul(newlength, 2), 1))
                                                // Copy over the first `submod` bytes of the new data as in
                                                // case 1 above.
                                                let slengthmod := mod(slength, 32)
                                                let mlengthmod := mod(mlength, 32)
                                                let submod := sub(32, slengthmod)
                                                let mc := add(_postBytes, submod)
                                                let end := add(_postBytes, mlength)
                                                let mask := sub(exp(0x100, submod), 1)
                                                sstore(sc, add(sload(sc), and(mload(mc), mask)))
                                                for {
                                                    sc := add(sc, 1)
                                                    mc := add(mc, 0x20)
                                                } lt(mc, end) {
                                                    sc := add(sc, 1)
                                                    mc := add(mc, 0x20)
                                                } {
                                                    sstore(sc, mload(mc))
                                                }
                                                mask := exp(0x100, sub(mc, end))
                                                sstore(sc, mul(div(mload(mc), mask), mask))
                                            }
                                        }
                                    }
                                    function slice(
                                        bytes memory _bytes,
                                        uint256 _start,
                                        uint256 _length
                                    )
                                        internal
                                        pure
                                        returns (bytes memory)
                                    {
                                        require(_length + 31 >= _length, "slice_overflow");
                                        require(_bytes.length >= _start + _length, "slice_outOfBounds");
                                        bytes memory tempBytes;
                                        assembly {
                                            switch iszero(_length)
                                            case 0 {
                                                // Get a location of some free memory and store it in tempBytes as
                                                // Solidity does for memory variables.
                                                tempBytes := mload(0x40)
                                                // The first word of the slice result is potentially a partial
                                                // word read from the original array. To read it, we calculate
                                                // the length of that partial word and start copying that many
                                                // bytes into the array. The first word we copy will start with
                                                // data we don't care about, but the last `lengthmod` bytes will
                                                // land at the beginning of the contents of the new array. When
                                                // we're done copying, we overwrite the full first word with
                                                // the actual length of the slice.
                                                let lengthmod := and(_length, 31)
                                                // The multiplication in the next line is necessary
                                                // because when slicing multiples of 32 bytes (lengthmod == 0)
                                                // the following copy loop was copying the origin's length
                                                // and then ending prematurely not copying everything it should.
                                                let mc := add(add(tempBytes, lengthmod), mul(0x20, iszero(lengthmod)))
                                                let end := add(mc, _length)
                                                for {
                                                    // The multiplication in the next line has the same exact purpose
                                                    // as the one above.
                                                    let cc := add(add(add(_bytes, lengthmod), mul(0x20, iszero(lengthmod))), _start)
                                                } lt(mc, end) {
                                                    mc := add(mc, 0x20)
                                                    cc := add(cc, 0x20)
                                                } {
                                                    mstore(mc, mload(cc))
                                                }
                                                mstore(tempBytes, _length)
                                                //update free-memory pointer
                                                //allocating the array padded to 32 bytes like the compiler does now
                                                mstore(0x40, and(add(mc, 31), not(31)))
                                            }
                                            //if we want a zero-length slice let's just return a zero-length array
                                            default {
                                                tempBytes := mload(0x40)
                                                //zero out the 32 bytes slice we are about to return
                                                //we need to do it because Solidity does not garbage collect
                                                mstore(tempBytes, 0)
                                                mstore(0x40, add(tempBytes, 0x20))
                                            }
                                        }
                                        return tempBytes;
                                    }
                                    function toAddress(bytes memory _bytes, uint256 _start) internal pure returns (address) {
                                        require(_bytes.length >= _start + 20, "toAddress_outOfBounds");
                                        address tempAddress;
                                        assembly {
                                            tempAddress := div(mload(add(add(_bytes, 0x20), _start)), 0x1000000000000000000000000)
                                        }
                                        return tempAddress;
                                    }
                                    function toUint8(bytes memory _bytes, uint256 _start) internal pure returns (uint8) {
                                        require(_bytes.length >= _start + 1 , "toUint8_outOfBounds");
                                        uint8 tempUint;
                                        assembly {
                                            tempUint := mload(add(add(_bytes, 0x1), _start))
                                        }
                                        return tempUint;
                                    }
                                    function toUint16(bytes memory _bytes, uint256 _start) internal pure returns (uint16) {
                                        require(_bytes.length >= _start + 2, "toUint16_outOfBounds");
                                        uint16 tempUint;
                                        assembly {
                                            tempUint := mload(add(add(_bytes, 0x2), _start))
                                        }
                                        return tempUint;
                                    }
                                    function toUint32(bytes memory _bytes, uint256 _start) internal pure returns (uint32) {
                                        require(_bytes.length >= _start + 4, "toUint32_outOfBounds");
                                        uint32 tempUint;
                                        assembly {
                                            tempUint := mload(add(add(_bytes, 0x4), _start))
                                        }
                                        return tempUint;
                                    }
                                    function toUint64(bytes memory _bytes, uint256 _start) internal pure returns (uint64) {
                                        require(_bytes.length >= _start + 8, "toUint64_outOfBounds");
                                        uint64 tempUint;
                                        assembly {
                                            tempUint := mload(add(add(_bytes, 0x8), _start))
                                        }
                                        return tempUint;
                                    }
                                    function toUint96(bytes memory _bytes, uint256 _start) internal pure returns (uint96) {
                                        require(_bytes.length >= _start + 12, "toUint96_outOfBounds");
                                        uint96 tempUint;
                                        assembly {
                                            tempUint := mload(add(add(_bytes, 0xc), _start))
                                        }
                                        return tempUint;
                                    }
                                    function toUint128(bytes memory _bytes, uint256 _start) internal pure returns (uint128) {
                                        require(_bytes.length >= _start + 16, "toUint128_outOfBounds");
                                        uint128 tempUint;
                                        assembly {
                                            tempUint := mload(add(add(_bytes, 0x10), _start))
                                        }
                                        return tempUint;
                                    }
                                    function toUint256(bytes memory _bytes, uint256 _start) internal pure returns (uint256) {
                                        require(_bytes.length >= _start + 32, "toUint256_outOfBounds");
                                        uint256 tempUint;
                                        assembly {
                                            tempUint := mload(add(add(_bytes, 0x20), _start))
                                        }
                                        return tempUint;
                                    }
                                    function toBytes32(bytes memory _bytes, uint256 _start) internal pure returns (bytes32) {
                                        require(_bytes.length >= _start + 32, "toBytes32_outOfBounds");
                                        bytes32 tempBytes32;
                                        assembly {
                                            tempBytes32 := mload(add(add(_bytes, 0x20), _start))
                                        }
                                        return tempBytes32;
                                    }
                                    function equal(bytes memory _preBytes, bytes memory _postBytes) internal pure returns (bool) {
                                        bool success = true;
                                        assembly {
                                            let length := mload(_preBytes)
                                            // if lengths don't match the arrays are not equal
                                            switch eq(length, mload(_postBytes))
                                            case 1 {
                                                // cb is a circuit breaker in the for loop since there's
                                                //  no said feature for inline assembly loops
                                                // cb = 1 - don't breaker
                                                // cb = 0 - break
                                                let cb := 1
                                                let mc := add(_preBytes, 0x20)
                                                let end := add(mc, length)
                                                for {
                                                    let cc := add(_postBytes, 0x20)
                                                // the next line is the loop condition:
                                                // while(uint256(mc < end) + cb == 2)
                                                } eq(add(lt(mc, end), cb), 2) {
                                                    mc := add(mc, 0x20)
                                                    cc := add(cc, 0x20)
                                                } {
                                                    // if any of these checks fails then arrays are not equal
                                                    if iszero(eq(mload(mc), mload(cc))) {
                                                        // unsuccess:
                                                        success := 0
                                                        cb := 0
                                                    }
                                                }
                                            }
                                            default {
                                                // unsuccess:
                                                success := 0
                                            }
                                        }
                                        return success;
                                    }
                                    function equalStorage(
                                        bytes storage _preBytes,
                                        bytes memory _postBytes
                                    )
                                        internal
                                        view
                                        returns (bool)
                                    {
                                        bool success = true;
                                        assembly {
                                            // we know _preBytes_offset is 0
                                            let fslot := sload(_preBytes.slot)
                                            // Decode the length of the stored array like in concatStorage().
                                            let slength := div(and(fslot, sub(mul(0x100, iszero(and(fslot, 1))), 1)), 2)
                                            let mlength := mload(_postBytes)
                                            // if lengths don't match the arrays are not equal
                                            switch eq(slength, mlength)
                                            case 1 {
                                                // slength can contain both the length and contents of the array
                                                // if length < 32 bytes so let's prepare for that
                                                // v. http://solidity.readthedocs.io/en/latest/miscellaneous.html#layout-of-state-variables-in-storage
                                                if iszero(iszero(slength)) {
                                                    switch lt(slength, 32)
                                                    case 1 {
                                                        // blank the last byte which is the length
                                                        fslot := mul(div(fslot, 0x100), 0x100)
                                                        if iszero(eq(fslot, mload(add(_postBytes, 0x20)))) {
                                                            // unsuccess:
                                                            success := 0
                                                        }
                                                    }
                                                    default {
                                                        // cb is a circuit breaker in the for loop since there's
                                                        //  no said feature for inline assembly loops
                                                        // cb = 1 - don't breaker
                                                        // cb = 0 - break
                                                        let cb := 1
                                                        // get the keccak hash to get the contents of the array
                                                        mstore(0x0, _preBytes.slot)
                                                        let sc := keccak256(0x0, 0x20)
                                                        let mc := add(_postBytes, 0x20)
                                                        let end := add(mc, mlength)
                                                        // the next line is the loop condition:
                                                        // while(uint256(mc < end) + cb == 2)
                                                        for {} eq(add(lt(mc, end), cb), 2) {
                                                            sc := add(sc, 1)
                                                            mc := add(mc, 0x20)
                                                        } {
                                                            if iszero(eq(sload(sc), mload(mc))) {
                                                                // unsuccess:
                                                                success := 0
                                                                cb := 0
                                                            }
                                                        }
                                                    }
                                                }
                                            }
                                            default {
                                                // unsuccess:
                                                success := 0
                                            }
                                        }
                                        return success;
                                    }
                                }
                                

                                File 4 of 4: Implementation
                                // contracts/Getters.sol
                                // SPDX-License-Identifier: Apache 2
                                pragma solidity ^0.8.0;
                                import "./State.sol";
                                contract Getters is State {
                                    function getGuardianSet(uint32 index) public view returns (Structs.GuardianSet memory) {
                                        return _state.guardianSets[index];
                                    }
                                    function getCurrentGuardianSetIndex() public view returns (uint32) {
                                        return _state.guardianSetIndex;
                                    }
                                    function getGuardianSetExpiry() public view returns (uint32) {
                                        return _state.guardianSetExpiry;
                                    }
                                    function governanceActionIsConsumed(bytes32 hash) public view returns (bool) {
                                        return _state.consumedGovernanceActions[hash];
                                    }
                                    function isInitialized(address impl) public view returns (bool) {
                                        return _state.initializedImplementations[impl];
                                    }
                                    function chainId() public view returns (uint16) {
                                        return _state.provider.chainId;
                                    }
                                    function governanceChainId() public view returns (uint16){
                                        return _state.provider.governanceChainId;
                                    }
                                    function governanceContract() public view returns (bytes32){
                                        return _state.provider.governanceContract;
                                    }
                                    function messageFee() public view returns (uint256) {
                                        return _state.messageFee;
                                    }
                                    function nextSequence(address emitter) public view returns (uint64) {
                                        return _state.sequences[emitter];
                                    }
                                }// contracts/Governance.sol
                                // SPDX-License-Identifier: Apache 2
                                pragma solidity ^0.8.0;
                                import "./Structs.sol";
                                import "./GovernanceStructs.sol";
                                import "./Messages.sol";
                                import "./Setters.sol";
                                import "@openzeppelin/contracts/proxy/ERC1967/ERC1967Upgrade.sol";
                                abstract contract Governance is GovernanceStructs, Messages, Setters, ERC1967Upgrade {
                                    event ContractUpgraded(address indexed oldContract, address indexed newContract);
                                    event GuardianSetAdded(uint32 indexed index);
                                    // "Core" (left padded)
                                    bytes32 constant module = 0x00000000000000000000000000000000000000000000000000000000436f7265;
                                    function submitContractUpgrade(bytes memory _vm) public {
                                        Structs.VM memory vm = parseVM(_vm);
                                        (bool isValid, string memory reason) = verifyGovernanceVM(vm);
                                        require(isValid, reason);
                                        GovernanceStructs.ContractUpgrade memory upgrade = parseContractUpgrade(vm.payload);
                                        require(upgrade.module == module, "Invalid Module");
                                        require(upgrade.chain == chainId(), "Invalid Chain");
                                        setGovernanceActionConsumed(vm.hash);
                                        upgradeImplementation(upgrade.newContract);
                                    }
                                    function submitSetMessageFee(bytes memory _vm) public {
                                        Structs.VM memory vm = parseVM(_vm);
                                        (bool isValid, string memory reason) = verifyGovernanceVM(vm);
                                        require(isValid, reason);
                                        GovernanceStructs.SetMessageFee memory upgrade = parseSetMessageFee(vm.payload);
                                        require(upgrade.module == module, "Invalid Module");
                                        require(upgrade.chain == chainId(), "Invalid Chain");
                                        setGovernanceActionConsumed(vm.hash);
                                        setMessageFee(upgrade.messageFee);
                                    }
                                    function submitNewGuardianSet(bytes memory _vm) public {
                                        Structs.VM memory vm = parseVM(_vm);
                                        (bool isValid, string memory reason) = verifyGovernanceVM(vm);
                                        require(isValid, reason);
                                        GovernanceStructs.GuardianSetUpgrade memory upgrade = parseGuardianSetUpgrade(vm.payload);
                                        require(upgrade.module == module, "invalid Module");
                                        require(upgrade.chain == chainId() || upgrade.chain == 0, "invalid Chain");
                                        require(upgrade.newGuardianSet.keys.length > 0, "new guardian set is empty");
                                        require(upgrade.newGuardianSetIndex == getCurrentGuardianSetIndex() + 1, "index must increase in steps of 1");
                                        setGovernanceActionConsumed(vm.hash);
                                        expireGuardianSet(getCurrentGuardianSetIndex());
                                        storeGuardianSet(upgrade.newGuardianSet, upgrade.newGuardianSetIndex);
                                        updateGuardianSetIndex(upgrade.newGuardianSetIndex);
                                    }
                                    function submitTransferFees(bytes memory _vm) public {
                                        Structs.VM memory vm = parseVM(_vm);
                                        (bool isValid, string memory reason) = verifyGovernanceVM(vm);
                                        require(isValid, reason);
                                        GovernanceStructs.TransferFees memory transfer = parseTransferFees(vm.payload);
                                        require(transfer.module == module, "invalid Module");
                                        require(transfer.chain == chainId() || transfer.chain == 0, "invalid Chain");
                                        setGovernanceActionConsumed(vm.hash);
                                        address payable recipient = payable(address(uint160(uint256(transfer.recipient))));
                                        recipient.transfer(transfer.amount);
                                    }
                                    function upgradeImplementation(address newImplementation) internal {
                                        address currentImplementation = _getImplementation();
                                        _upgradeTo(newImplementation);
                                        // Call initialize function of the new implementation
                                        (bool success, bytes memory reason) = newImplementation.delegatecall(abi.encodeWithSignature("initialize()"));
                                        require(success, string(reason));
                                        emit ContractUpgraded(currentImplementation, newImplementation);
                                    }
                                    function verifyGovernanceVM(Structs.VM memory vm) internal view returns (bool, string memory){
                                        // validate vm
                                        (bool isValid, string memory reason) = verifyVM(vm);
                                        if (!isValid){
                                            return (false, reason);
                                        }
                                        // only current guardianset can sign governance packets
                                        if (vm.guardianSetIndex != getCurrentGuardianSetIndex()) {
                                            return (false, "not signed by current guardian set");
                                        }
                                        // verify source
                                        if (uint16(vm.emitterChainId) != governanceChainId()) {
                                            return (false, "wrong governance chain");
                                        }
                                        if (vm.emitterAddress != governanceContract()) {
                                            return (false, "wrong governance contract");
                                        }
                                        // prevent re-entry
                                        if (governanceActionIsConsumed(vm.hash)){
                                            return (false, "governance action already consumed");
                                        }
                                        return (true, "");
                                    }
                                }// contracts/GovernanceStructs.sol
                                // SPDX-License-Identifier: Apache 2
                                pragma solidity ^0.8.0;
                                import "./libraries/external/BytesLib.sol";
                                import "./Structs.sol";
                                contract GovernanceStructs {
                                    using BytesLib for bytes;
                                    enum GovernanceAction {
                                        UpgradeContract,
                                        UpgradeGuardianset
                                    }
                                    struct ContractUpgrade {
                                        bytes32 module;
                                        uint8 action;
                                        uint16 chain;
                                        address newContract;
                                    }
                                    struct GuardianSetUpgrade {
                                        bytes32 module;
                                        uint8 action;
                                        uint16 chain;
                                        Structs.GuardianSet newGuardianSet;
                                        uint32 newGuardianSetIndex;
                                    }
                                    struct SetMessageFee {
                                        bytes32 module;
                                        uint8 action;
                                        uint16 chain;
                                        uint256 messageFee;
                                    }
                                    struct TransferFees {
                                        bytes32 module;
                                        uint8 action;
                                        uint16 chain;
                                        uint256 amount;
                                        bytes32 recipient;
                                    }
                                    function parseContractUpgrade(bytes memory encodedUpgrade) public pure returns (ContractUpgrade memory cu) {
                                        uint index = 0;
                                        cu.module = encodedUpgrade.toBytes32(index);
                                        index += 32;
                                        cu.action = encodedUpgrade.toUint8(index);
                                        index += 1;
                                        require(cu.action == 1, "invalid ContractUpgrade");
                                        cu.chain = encodedUpgrade.toUint16(index);
                                        index += 2;
                                        cu.newContract = address(uint160(uint256(encodedUpgrade.toBytes32(index))));
                                        index += 32;
                                        require(encodedUpgrade.length == index, "invalid ContractUpgrade");
                                    }
                                    function parseGuardianSetUpgrade(bytes memory encodedUpgrade) public pure returns (GuardianSetUpgrade memory gsu) {
                                        uint index = 0;
                                        gsu.module = encodedUpgrade.toBytes32(index);
                                        index += 32;
                                        gsu.action = encodedUpgrade.toUint8(index);
                                        index += 1;
                                        require(gsu.action == 2, "invalid GuardianSetUpgrade");
                                        gsu.chain = encodedUpgrade.toUint16(index);
                                        index += 2;
                                        gsu.newGuardianSetIndex = encodedUpgrade.toUint32(index);
                                        index += 4;
                                        uint8 guardianLength = encodedUpgrade.toUint8(index);
                                        index += 1;
                                        gsu.newGuardianSet = Structs.GuardianSet({
                                            keys : new address[](guardianLength),
                                            expirationTime : 0
                                        });
                                        for(uint i = 0; i < guardianLength; i++) {
                                            gsu.newGuardianSet.keys[i] = encodedUpgrade.toAddress(index);
                                            index += 20;
                                        }
                                        require(encodedUpgrade.length == index, "invalid GuardianSetUpgrade");
                                    }
                                    function parseSetMessageFee(bytes memory encodedSetMessageFee) public pure returns (SetMessageFee memory smf) {
                                        uint index = 0;
                                        smf.module = encodedSetMessageFee.toBytes32(index);
                                        index += 32;
                                        smf.action = encodedSetMessageFee.toUint8(index);
                                        index += 1;
                                        require(smf.action == 3, "invalid SetMessageFee");
                                        smf.chain = encodedSetMessageFee.toUint16(index);
                                        index += 2;
                                        smf.messageFee = encodedSetMessageFee.toUint256(index);
                                        index += 32;
                                        require(encodedSetMessageFee.length == index, "invalid SetMessageFee");
                                    }
                                    function parseTransferFees(bytes memory encodedTransferFees) public pure returns (TransferFees memory tf) {
                                        uint index = 0;
                                        tf.module = encodedTransferFees.toBytes32(index);
                                        index += 32;
                                        tf.action = encodedTransferFees.toUint8(index);
                                        index += 1;
                                        require(tf.action == 4, "invalid TransferFees");
                                        tf.chain = encodedTransferFees.toUint16(index);
                                        index += 2;
                                        tf.amount = encodedTransferFees.toUint256(index);
                                        index += 32;
                                        tf.recipient = encodedTransferFees.toBytes32(index);
                                        index += 32;
                                        require(encodedTransferFees.length == index, "invalid TransferFees");
                                    }
                                }// contracts/Implementation.sol
                                // SPDX-License-Identifier: Apache 2
                                pragma solidity ^0.8.0;
                                pragma experimental ABIEncoderV2;
                                import "./Governance.sol";
                                import "@openzeppelin/contracts/proxy/ERC1967/ERC1967Upgrade.sol";
                                contract Implementation is Governance {
                                    event LogMessagePublished(address indexed sender, uint64 sequence, uint32 nonce, bytes payload, uint8 consistencyLevel);
                                    // Publish a message to be attested by the Wormhole network
                                    function publishMessage(
                                        uint32 nonce,
                                        bytes memory payload,
                                        uint8 consistencyLevel
                                    ) public payable returns (uint64 sequence) {
                                        // check fee
                                        require(msg.value == messageFee(), "invalid fee");
                                        sequence = useSequence(msg.sender);
                                        // emit log
                                        emit LogMessagePublished(msg.sender, sequence, nonce, payload, consistencyLevel);
                                    }
                                    function useSequence(address emitter) internal returns (uint64 sequence) {
                                        sequence = nextSequence(emitter);
                                        setNextSequence(emitter, sequence + 1);
                                    }
                                    function initialize(address[] memory initialGuardians, uint16 chainId, uint16 governanceChainId, bytes32 governanceContract) initializer public {
                                        require(initialGuardians.length > 0, "no guardians specified");
                                        Structs.GuardianSet memory initialGuardianSet = Structs.GuardianSet({
                                            keys : initialGuardians,
                                            expirationTime : 0
                                        });
                                        storeGuardianSet(initialGuardianSet, 0);
                                        // initial guardian set index is 0, which is the default value of the storage slot anyways
                                        setChainId(chainId);
                                        setGovernanceChainId(governanceChainId);
                                        setGovernanceContract(governanceContract);
                                    }
                                    modifier initializer() {
                                        address implementation = ERC1967Upgrade._getImplementation();
                                        require(
                                            !isInitialized(implementation),
                                            "already initialized"
                                        );
                                        setInitialized(implementation);
                                        _;
                                    }
                                    fallback() external payable {revert("unsupported");}
                                    receive() external payable {revert("the Wormhole contract does not accept assets");}
                                }
                                // contracts/Messages.sol
                                // SPDX-License-Identifier: Apache 2
                                pragma solidity ^0.8.0;
                                pragma experimental ABIEncoderV2;
                                import "./Getters.sol";
                                import "./Structs.sol";
                                import "./libraries/external/BytesLib.sol";
                                contract Messages is Getters {
                                    using BytesLib for bytes;
                                    function parseAndVerifyVM(bytes calldata encodedVM) public view returns (Structs.VM memory vm, bool valid, string memory reason) {
                                        vm = parseVM(encodedVM);
                                        (valid, reason) = verifyVM(vm);
                                    }
                                    function verifyVM(Structs.VM memory vm) public view returns (bool valid, string memory reason) {
                                        Structs.GuardianSet memory guardianSet = getGuardianSet(vm.guardianSetIndex);
                                        if(guardianSet.keys.length == 0){
                                            return (false, "invalid guardian set");
                                        }
                                        if(vm.guardianSetIndex != getCurrentGuardianSetIndex() && guardianSet.expirationTime < block.timestamp){
                                            return (false, "guardian set has expired");
                                        }
                                        // We're using a fixed point number transformation with 1 decimal to deal with rounding.
                                        if(((guardianSet.keys.length * 10 / 3) * 2) / 10 + 1 > vm.signatures.length){
                                            return (false, "no quorum");
                                        }
                                        // Verify signatures
                                        (bool signaturesValid, string memory invalidReason) = verifySignatures(vm.hash, vm.signatures, guardianSet);
                                        if(!signaturesValid){
                                            return (false, invalidReason);
                                        }
                                        return (true, "");
                                    }
                                    function verifySignatures(bytes32 hash, Structs.Signature[] memory signatures, Structs.GuardianSet memory guardianSet) public pure returns (bool valid, string memory reason) {
                                        uint8 lastIndex = 0;
                                        for (uint i = 0; i < signatures.length; i++) {
                                            Structs.Signature memory sig = signatures[i];
                                            require(i == 0 || sig.guardianIndex > lastIndex, "signature indices must be ascending");
                                            lastIndex = sig.guardianIndex;
                                            if(ecrecover(hash, sig.v, sig.r, sig.s) != guardianSet.keys[sig.guardianIndex]){
                                                return (false, "VM signature invalid");
                                            }
                                        }
                                        return (true, "");
                                    }
                                    function parseVM(bytes memory encodedVM) public pure virtual returns (Structs.VM memory vm) {
                                        uint index = 0;
                                        vm.version = encodedVM.toUint8(index);
                                        index += 1;
                                        require(vm.version == 1, "VM version incompatible");
                                        vm.guardianSetIndex = encodedVM.toUint32(index);
                                        index += 4;
                                        // Parse Signatures
                                        uint256 signersLen = encodedVM.toUint8(index);
                                        index += 1;
                                        vm.signatures = new Structs.Signature[](signersLen);
                                        for (uint i = 0; i < signersLen; i++) {
                                            vm.signatures[i].guardianIndex = encodedVM.toUint8(index);
                                            index += 1;
                                            vm.signatures[i].r = encodedVM.toBytes32(index);
                                            index += 32;
                                            vm.signatures[i].s = encodedVM.toBytes32(index);
                                            index += 32;
                                            vm.signatures[i].v = encodedVM.toUint8(index) + 27;
                                            index += 1;
                                        }
                                        // Hash the body
                                        bytes memory body = encodedVM.slice(index, encodedVM.length - index);
                                        vm.hash = keccak256(abi.encodePacked(keccak256(body)));
                                        // Parse the body
                                        vm.timestamp = encodedVM.toUint32(index);
                                        index += 4;
                                        vm.nonce = encodedVM.toUint32(index);
                                        index += 4;
                                        vm.emitterChainId = encodedVM.toUint16(index);
                                        index += 2;
                                        vm.emitterAddress = encodedVM.toBytes32(index);
                                        index += 32;
                                        vm.sequence = encodedVM.toUint64(index);
                                        index += 8;
                                        vm.consistencyLevel = encodedVM.toUint8(index);
                                        index += 1;
                                        vm.payload = encodedVM.slice(index, encodedVM.length - index);
                                    }
                                }
                                // contracts/Setters.sol
                                // SPDX-License-Identifier: Apache 2
                                pragma solidity ^0.8.0;
                                import "./State.sol";
                                contract Setters is State {
                                    function updateGuardianSetIndex(uint32 newIndex) internal {
                                        _state.guardianSetIndex = newIndex;
                                    }
                                    function expireGuardianSet(uint32 index) internal {
                                        _state.guardianSets[index].expirationTime = uint32(block.timestamp) + 86400;
                                    }
                                    function storeGuardianSet(Structs.GuardianSet memory set, uint32 index) internal {
                                        _state.guardianSets[index] = set;
                                    }
                                    function setInitialized(address implementatiom) internal {
                                        _state.initializedImplementations[implementatiom] = true;
                                    }
                                    function setGovernanceActionConsumed(bytes32 hash) internal {
                                        _state.consumedGovernanceActions[hash] = true;
                                    }
                                    function setChainId(uint16 chainId) internal {
                                        _state.provider.chainId = chainId;
                                    }
                                    function setGovernanceChainId(uint16 chainId) internal {
                                        _state.provider.governanceChainId = chainId;
                                    }
                                    function setGovernanceContract(bytes32 governanceContract) internal {
                                        _state.provider.governanceContract = governanceContract;
                                    }
                                    function setMessageFee(uint256 newFee) internal {
                                        _state.messageFee = newFee;
                                    }
                                    function setNextSequence(address emitter, uint64 sequence) internal {
                                        _state.sequences[emitter] = sequence;
                                    }
                                }// contracts/State.sol
                                // SPDX-License-Identifier: Apache 2
                                pragma solidity ^0.8.0;
                                import "./Structs.sol";
                                contract Events {
                                    event LogGuardianSetChanged(
                                        uint32 oldGuardianIndex,
                                        uint32 newGuardianIndex
                                    );
                                    event LogMessagePublished(
                                        address emitter_address,
                                        uint32 nonce,
                                        bytes payload
                                    );
                                }
                                contract Storage {
                                    struct WormholeState {
                                        Structs.Provider provider;
                                        // Mapping of guardian_set_index => guardian set
                                        mapping(uint32 => Structs.GuardianSet) guardianSets;
                                        // Current active guardian set index
                                        uint32 guardianSetIndex;
                                        // Period for which a guardian set stays active after it has been replaced
                                        uint32 guardianSetExpiry;
                                        // Sequence numbers per emitter
                                        mapping(address => uint64) sequences;
                                        // Mapping of consumed governance actions
                                        mapping(bytes32 => bool) consumedGovernanceActions;
                                        // Mapping of initialized implementations
                                        mapping(address => bool) initializedImplementations;
                                        uint256 messageFee;
                                    }
                                }
                                contract State {
                                    Storage.WormholeState _state;
                                }// contracts/Structs.sol
                                // SPDX-License-Identifier: Apache 2
                                pragma solidity ^0.8.0;
                                interface Structs {
                                \tstruct Provider {
                                \t\tuint16 chainId;
                                \t\tuint16 governanceChainId;
                                \t\tbytes32 governanceContract;
                                \t}
                                \tstruct GuardianSet {
                                \t\taddress[] keys;
                                \t\tuint32 expirationTime;
                                \t}
                                \tstruct Signature {
                                \t\tbytes32 r;
                                \t\tbytes32 s;
                                \t\tuint8 v;
                                \t\tuint8 guardianIndex;
                                \t}
                                \tstruct VM {
                                \t\tuint8 version;
                                \t\tuint32 timestamp;
                                \t\tuint32 nonce;
                                \t\tuint16 emitterChainId;
                                \t\tbytes32 emitterAddress;
                                \t\tuint64 sequence;
                                \t\tuint8 consistencyLevel;
                                \t\tbytes payload;
                                \t\tuint32 guardianSetIndex;
                                \t\tSignature[] signatures;
                                \t\tbytes32 hash;
                                \t}
                                }
                                // SPDX-License-Identifier: Unlicense
                                /*
                                 * @title Solidity Bytes Arrays Utils
                                 * @author Gonçalo Sá <[email protected]>
                                 *
                                 * @dev Bytes tightly packed arrays utility library for ethereum contracts written in Solidity.
                                 *      The library lets you concatenate, slice and type cast bytes arrays both in memory and storage.
                                 */
                                pragma solidity >=0.8.0 <0.9.0;
                                library BytesLib {
                                    function concat(
                                        bytes memory _preBytes,
                                        bytes memory _postBytes
                                    )
                                        internal
                                        pure
                                        returns (bytes memory)
                                    {
                                        bytes memory tempBytes;
                                        assembly {
                                            // Get a location of some free memory and store it in tempBytes as
                                            // Solidity does for memory variables.
                                            tempBytes := mload(0x40)
                                            // Store the length of the first bytes array at the beginning of
                                            // the memory for tempBytes.
                                            let length := mload(_preBytes)
                                            mstore(tempBytes, length)
                                            // Maintain a memory counter for the current write location in the
                                            // temp bytes array by adding the 32 bytes for the array length to
                                            // the starting location.
                                            let mc := add(tempBytes, 0x20)
                                            // Stop copying when the memory counter reaches the length of the
                                            // first bytes array.
                                            let end := add(mc, length)
                                            for {
                                                // Initialize a copy counter to the start of the _preBytes data,
                                                // 32 bytes into its memory.
                                                let cc := add(_preBytes, 0x20)
                                            } lt(mc, end) {
                                                // Increase both counters by 32 bytes each iteration.
                                                mc := add(mc, 0x20)
                                                cc := add(cc, 0x20)
                                            } {
                                                // Write the _preBytes data into the tempBytes memory 32 bytes
                                                // at a time.
                                                mstore(mc, mload(cc))
                                            }
                                            // Add the length of _postBytes to the current length of tempBytes
                                            // and store it as the new length in the first 32 bytes of the
                                            // tempBytes memory.
                                            length := mload(_postBytes)
                                            mstore(tempBytes, add(length, mload(tempBytes)))
                                            // Move the memory counter back from a multiple of 0x20 to the
                                            // actual end of the _preBytes data.
                                            mc := end
                                            // Stop copying when the memory counter reaches the new combined
                                            // length of the arrays.
                                            end := add(mc, length)
                                            for {
                                                let cc := add(_postBytes, 0x20)
                                            } lt(mc, end) {
                                                mc := add(mc, 0x20)
                                                cc := add(cc, 0x20)
                                            } {
                                                mstore(mc, mload(cc))
                                            }
                                            // Update the free-memory pointer by padding our last write location
                                            // to 32 bytes: add 31 bytes to the end of tempBytes to move to the
                                            // next 32 byte block, then round down to the nearest multiple of
                                            // 32. If the sum of the length of the two arrays is zero then add
                                            // one before rounding down to leave a blank 32 bytes (the length block with 0).
                                            mstore(0x40, and(
                                              add(add(end, iszero(add(length, mload(_preBytes)))), 31),
                                              not(31) // Round down to the nearest 32 bytes.
                                            ))
                                        }
                                        return tempBytes;
                                    }
                                    function concatStorage(bytes storage _preBytes, bytes memory _postBytes) internal {
                                        assembly {
                                            // Read the first 32 bytes of _preBytes storage, which is the length
                                            // of the array. (We don't need to use the offset into the slot
                                            // because arrays use the entire slot.)
                                            let fslot := sload(_preBytes.slot)
                                            // Arrays of 31 bytes or less have an even value in their slot,
                                            // while longer arrays have an odd value. The actual length is
                                            // the slot divided by two for odd values, and the lowest order
                                            // byte divided by two for even values.
                                            // If the slot is even, bitwise and the slot with 255 and divide by
                                            // two to get the length. If the slot is odd, bitwise and the slot
                                            // with -1 and divide by two.
                                            let slength := div(and(fslot, sub(mul(0x100, iszero(and(fslot, 1))), 1)), 2)
                                            let mlength := mload(_postBytes)
                                            let newlength := add(slength, mlength)
                                            // slength can contain both the length and contents of the array
                                            // if length < 32 bytes so let's prepare for that
                                            // v. http://solidity.readthedocs.io/en/latest/miscellaneous.html#layout-of-state-variables-in-storage
                                            switch add(lt(slength, 32), lt(newlength, 32))
                                            case 2 {
                                                // Since the new array still fits in the slot, we just need to
                                                // update the contents of the slot.
                                                // uint256(bytes_storage) = uint256(bytes_storage) + uint256(bytes_memory) + new_length
                                                sstore(
                                                    _preBytes.slot,
                                                    // all the modifications to the slot are inside this
                                                    // next block
                                                    add(
                                                        // we can just add to the slot contents because the
                                                        // bytes we want to change are the LSBs
                                                        fslot,
                                                        add(
                                                            mul(
                                                                div(
                                                                    // load the bytes from memory
                                                                    mload(add(_postBytes, 0x20)),
                                                                    // zero all bytes to the right
                                                                    exp(0x100, sub(32, mlength))
                                                                ),
                                                                // and now shift left the number of bytes to
                                                                // leave space for the length in the slot
                                                                exp(0x100, sub(32, newlength))
                                                            ),
                                                            // increase length by the double of the memory
                                                            // bytes length
                                                            mul(mlength, 2)
                                                        )
                                                    )
                                                )
                                            }
                                            case 1 {
                                                // The stored value fits in the slot, but the combined value
                                                // will exceed it.
                                                // get the keccak hash to get the contents of the array
                                                mstore(0x0, _preBytes.slot)
                                                let sc := add(keccak256(0x0, 0x20), div(slength, 32))
                                                // save new length
                                                sstore(_preBytes.slot, add(mul(newlength, 2), 1))
                                                // The contents of the _postBytes array start 32 bytes into
                                                // the structure. Our first read should obtain the `submod`
                                                // bytes that can fit into the unused space in the last word
                                                // of the stored array. To get this, we read 32 bytes starting
                                                // from `submod`, so the data we read overlaps with the array
                                                // contents by `submod` bytes. Masking the lowest-order
                                                // `submod` bytes allows us to add that value directly to the
                                                // stored value.
                                                let submod := sub(32, slength)
                                                let mc := add(_postBytes, submod)
                                                let end := add(_postBytes, mlength)
                                                let mask := sub(exp(0x100, submod), 1)
                                                sstore(
                                                    sc,
                                                    add(
                                                        and(
                                                            fslot,
                                                            0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff00
                                                        ),
                                                        and(mload(mc), mask)
                                                    )
                                                )
                                                for {
                                                    mc := add(mc, 0x20)
                                                    sc := add(sc, 1)
                                                } lt(mc, end) {
                                                    sc := add(sc, 1)
                                                    mc := add(mc, 0x20)
                                                } {
                                                    sstore(sc, mload(mc))
                                                }
                                                mask := exp(0x100, sub(mc, end))
                                                sstore(sc, mul(div(mload(mc), mask), mask))
                                            }
                                            default {
                                                // get the keccak hash to get the contents of the array
                                                mstore(0x0, _preBytes.slot)
                                                // Start copying to the last used word of the stored array.
                                                let sc := add(keccak256(0x0, 0x20), div(slength, 32))
                                                // save new length
                                                sstore(_preBytes.slot, add(mul(newlength, 2), 1))
                                                // Copy over the first `submod` bytes of the new data as in
                                                // case 1 above.
                                                let slengthmod := mod(slength, 32)
                                                let mlengthmod := mod(mlength, 32)
                                                let submod := sub(32, slengthmod)
                                                let mc := add(_postBytes, submod)
                                                let end := add(_postBytes, mlength)
                                                let mask := sub(exp(0x100, submod), 1)
                                                sstore(sc, add(sload(sc), and(mload(mc), mask)))
                                                for {
                                                    sc := add(sc, 1)
                                                    mc := add(mc, 0x20)
                                                } lt(mc, end) {
                                                    sc := add(sc, 1)
                                                    mc := add(mc, 0x20)
                                                } {
                                                    sstore(sc, mload(mc))
                                                }
                                                mask := exp(0x100, sub(mc, end))
                                                sstore(sc, mul(div(mload(mc), mask), mask))
                                            }
                                        }
                                    }
                                    function slice(
                                        bytes memory _bytes,
                                        uint256 _start,
                                        uint256 _length
                                    )
                                        internal
                                        pure
                                        returns (bytes memory)
                                    {
                                        require(_length + 31 >= _length, "slice_overflow");
                                        require(_bytes.length >= _start + _length, "slice_outOfBounds");
                                        bytes memory tempBytes;
                                        assembly {
                                            switch iszero(_length)
                                            case 0 {
                                                // Get a location of some free memory and store it in tempBytes as
                                                // Solidity does for memory variables.
                                                tempBytes := mload(0x40)
                                                // The first word of the slice result is potentially a partial
                                                // word read from the original array. To read it, we calculate
                                                // the length of that partial word and start copying that many
                                                // bytes into the array. The first word we copy will start with
                                                // data we don't care about, but the last `lengthmod` bytes will
                                                // land at the beginning of the contents of the new array. When
                                                // we're done copying, we overwrite the full first word with
                                                // the actual length of the slice.
                                                let lengthmod := and(_length, 31)
                                                // The multiplication in the next line is necessary
                                                // because when slicing multiples of 32 bytes (lengthmod == 0)
                                                // the following copy loop was copying the origin's length
                                                // and then ending prematurely not copying everything it should.
                                                let mc := add(add(tempBytes, lengthmod), mul(0x20, iszero(lengthmod)))
                                                let end := add(mc, _length)
                                                for {
                                                    // The multiplication in the next line has the same exact purpose
                                                    // as the one above.
                                                    let cc := add(add(add(_bytes, lengthmod), mul(0x20, iszero(lengthmod))), _start)
                                                } lt(mc, end) {
                                                    mc := add(mc, 0x20)
                                                    cc := add(cc, 0x20)
                                                } {
                                                    mstore(mc, mload(cc))
                                                }
                                                mstore(tempBytes, _length)
                                                //update free-memory pointer
                                                //allocating the array padded to 32 bytes like the compiler does now
                                                mstore(0x40, and(add(mc, 31), not(31)))
                                            }
                                            //if we want a zero-length slice let's just return a zero-length array
                                            default {
                                                tempBytes := mload(0x40)
                                                //zero out the 32 bytes slice we are about to return
                                                //we need to do it because Solidity does not garbage collect
                                                mstore(tempBytes, 0)
                                                mstore(0x40, add(tempBytes, 0x20))
                                            }
                                        }
                                        return tempBytes;
                                    }
                                    function toAddress(bytes memory _bytes, uint256 _start) internal pure returns (address) {
                                        require(_bytes.length >= _start + 20, "toAddress_outOfBounds");
                                        address tempAddress;
                                        assembly {
                                            tempAddress := div(mload(add(add(_bytes, 0x20), _start)), 0x1000000000000000000000000)
                                        }
                                        return tempAddress;
                                    }
                                    function toUint8(bytes memory _bytes, uint256 _start) internal pure returns (uint8) {
                                        require(_bytes.length >= _start + 1 , "toUint8_outOfBounds");
                                        uint8 tempUint;
                                        assembly {
                                            tempUint := mload(add(add(_bytes, 0x1), _start))
                                        }
                                        return tempUint;
                                    }
                                    function toUint16(bytes memory _bytes, uint256 _start) internal pure returns (uint16) {
                                        require(_bytes.length >= _start + 2, "toUint16_outOfBounds");
                                        uint16 tempUint;
                                        assembly {
                                            tempUint := mload(add(add(_bytes, 0x2), _start))
                                        }
                                        return tempUint;
                                    }
                                    function toUint32(bytes memory _bytes, uint256 _start) internal pure returns (uint32) {
                                        require(_bytes.length >= _start + 4, "toUint32_outOfBounds");
                                        uint32 tempUint;
                                        assembly {
                                            tempUint := mload(add(add(_bytes, 0x4), _start))
                                        }
                                        return tempUint;
                                    }
                                    function toUint64(bytes memory _bytes, uint256 _start) internal pure returns (uint64) {
                                        require(_bytes.length >= _start + 8, "toUint64_outOfBounds");
                                        uint64 tempUint;
                                        assembly {
                                            tempUint := mload(add(add(_bytes, 0x8), _start))
                                        }
                                        return tempUint;
                                    }
                                    function toUint96(bytes memory _bytes, uint256 _start) internal pure returns (uint96) {
                                        require(_bytes.length >= _start + 12, "toUint96_outOfBounds");
                                        uint96 tempUint;
                                        assembly {
                                            tempUint := mload(add(add(_bytes, 0xc), _start))
                                        }
                                        return tempUint;
                                    }
                                    function toUint128(bytes memory _bytes, uint256 _start) internal pure returns (uint128) {
                                        require(_bytes.length >= _start + 16, "toUint128_outOfBounds");
                                        uint128 tempUint;
                                        assembly {
                                            tempUint := mload(add(add(_bytes, 0x10), _start))
                                        }
                                        return tempUint;
                                    }
                                    function toUint256(bytes memory _bytes, uint256 _start) internal pure returns (uint256) {
                                        require(_bytes.length >= _start + 32, "toUint256_outOfBounds");
                                        uint256 tempUint;
                                        assembly {
                                            tempUint := mload(add(add(_bytes, 0x20), _start))
                                        }
                                        return tempUint;
                                    }
                                    function toBytes32(bytes memory _bytes, uint256 _start) internal pure returns (bytes32) {
                                        require(_bytes.length >= _start + 32, "toBytes32_outOfBounds");
                                        bytes32 tempBytes32;
                                        assembly {
                                            tempBytes32 := mload(add(add(_bytes, 0x20), _start))
                                        }
                                        return tempBytes32;
                                    }
                                    function equal(bytes memory _preBytes, bytes memory _postBytes) internal pure returns (bool) {
                                        bool success = true;
                                        assembly {
                                            let length := mload(_preBytes)
                                            // if lengths don't match the arrays are not equal
                                            switch eq(length, mload(_postBytes))
                                            case 1 {
                                                // cb is a circuit breaker in the for loop since there's
                                                //  no said feature for inline assembly loops
                                                // cb = 1 - don't breaker
                                                // cb = 0 - break
                                                let cb := 1
                                                let mc := add(_preBytes, 0x20)
                                                let end := add(mc, length)
                                                for {
                                                    let cc := add(_postBytes, 0x20)
                                                // the next line is the loop condition:
                                                // while(uint256(mc < end) + cb == 2)
                                                } eq(add(lt(mc, end), cb), 2) {
                                                    mc := add(mc, 0x20)
                                                    cc := add(cc, 0x20)
                                                } {
                                                    // if any of these checks fails then arrays are not equal
                                                    if iszero(eq(mload(mc), mload(cc))) {
                                                        // unsuccess:
                                                        success := 0
                                                        cb := 0
                                                    }
                                                }
                                            }
                                            default {
                                                // unsuccess:
                                                success := 0
                                            }
                                        }
                                        return success;
                                    }
                                    function equalStorage(
                                        bytes storage _preBytes,
                                        bytes memory _postBytes
                                    )
                                        internal
                                        view
                                        returns (bool)
                                    {
                                        bool success = true;
                                        assembly {
                                            // we know _preBytes_offset is 0
                                            let fslot := sload(_preBytes.slot)
                                            // Decode the length of the stored array like in concatStorage().
                                            let slength := div(and(fslot, sub(mul(0x100, iszero(and(fslot, 1))), 1)), 2)
                                            let mlength := mload(_postBytes)
                                            // if lengths don't match the arrays are not equal
                                            switch eq(slength, mlength)
                                            case 1 {
                                                // slength can contain both the length and contents of the array
                                                // if length < 32 bytes so let's prepare for that
                                                // v. http://solidity.readthedocs.io/en/latest/miscellaneous.html#layout-of-state-variables-in-storage
                                                if iszero(iszero(slength)) {
                                                    switch lt(slength, 32)
                                                    case 1 {
                                                        // blank the last byte which is the length
                                                        fslot := mul(div(fslot, 0x100), 0x100)
                                                        if iszero(eq(fslot, mload(add(_postBytes, 0x20)))) {
                                                            // unsuccess:
                                                            success := 0
                                                        }
                                                    }
                                                    default {
                                                        // cb is a circuit breaker in the for loop since there's
                                                        //  no said feature for inline assembly loops
                                                        // cb = 1 - don't breaker
                                                        // cb = 0 - break
                                                        let cb := 1
                                                        // get the keccak hash to get the contents of the array
                                                        mstore(0x0, _preBytes.slot)
                                                        let sc := keccak256(0x0, 0x20)
                                                        let mc := add(_postBytes, 0x20)
                                                        let end := add(mc, mlength)
                                                        // the next line is the loop condition:
                                                        // while(uint256(mc < end) + cb == 2)
                                                        for {} eq(add(lt(mc, end), cb), 2) {
                                                            sc := add(sc, 1)
                                                            mc := add(mc, 0x20)
                                                        } {
                                                            if iszero(eq(sload(sc), mload(mc))) {
                                                                // unsuccess:
                                                                success := 0
                                                                cb := 0
                                                            }
                                                        }
                                                    }
                                                }
                                            }
                                            default {
                                                // unsuccess:
                                                success := 0
                                            }
                                        }
                                        return success;
                                    }
                                }
                                // SPDX-License-Identifier: MIT
                                pragma solidity ^0.8.2;
                                import "../beacon/IBeacon.sol";
                                import "../../utils/Address.sol";
                                import "../../utils/StorageSlot.sol";
                                /**
                                 * @dev This abstract contract provides getters and event emitting update functions for
                                 * https://eips.ethereum.org/EIPS/eip-1967[EIP1967] slots.
                                 *
                                 * _Available since v4.1._
                                 *
                                 * @custom:oz-upgrades-unsafe-allow delegatecall
                                 */
                                abstract contract ERC1967Upgrade {
                                    // This is the keccak-256 hash of "eip1967.proxy.rollback" subtracted by 1
                                    bytes32 private constant _ROLLBACK_SLOT = 0x4910fdfa16fed3260ed0e7147f7cc6da11a60208b5b9406d12a635614ffd9143;
                                    /**
                                     * @dev Storage slot with the address of the current implementation.
                                     * This is the keccak-256 hash of "eip1967.proxy.implementation" subtracted by 1, and is
                                     * validated in the constructor.
                                     */
                                    bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
                                    /**
                                     * @dev Emitted when the implementation is upgraded.
                                     */
                                    event Upgraded(address indexed implementation);
                                    /**
                                     * @dev Returns the current implementation address.
                                     */
                                    function _getImplementation() internal view returns (address) {
                                        return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
                                    }
                                    /**
                                     * @dev Stores a new address in the EIP1967 implementation slot.
                                     */
                                    function _setImplementation(address newImplementation) private {
                                        require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
                                        StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
                                    }
                                    /**
                                     * @dev Perform implementation upgrade
                                     *
                                     * Emits an {Upgraded} event.
                                     */
                                    function _upgradeTo(address newImplementation) internal {
                                        _setImplementation(newImplementation);
                                        emit Upgraded(newImplementation);
                                    }
                                    /**
                                     * @dev Perform implementation upgrade with additional setup call.
                                     *
                                     * Emits an {Upgraded} event.
                                     */
                                    function _upgradeToAndCall(address newImplementation, bytes memory data, bool forceCall) internal {
                                        _setImplementation(newImplementation);
                                        emit Upgraded(newImplementation);
                                        if (data.length > 0 || forceCall) {
                                            Address.functionDelegateCall(newImplementation, data);
                                        }
                                    }
                                    /**
                                     * @dev Perform implementation upgrade with security checks for UUPS proxies, and additional setup call.
                                     *
                                     * Emits an {Upgraded} event.
                                     */
                                    function _upgradeToAndCallSecure(address newImplementation, bytes memory data, bool forceCall) internal {
                                        address oldImplementation = _getImplementation();
                                        // Initial upgrade and setup call
                                        _setImplementation(newImplementation);
                                        if (data.length > 0 || forceCall) {
                                            Address.functionDelegateCall(newImplementation, data);
                                        }
                                        // Perform rollback test if not already in progress
                                        StorageSlot.BooleanSlot storage rollbackTesting = StorageSlot.getBooleanSlot(_ROLLBACK_SLOT);
                                        if (!rollbackTesting.value) {
                                            // Trigger rollback using upgradeTo from the new implementation
                                            rollbackTesting.value = true;
                                            Address.functionDelegateCall(
                                                newImplementation,
                                                abi.encodeWithSignature(
                                                    "upgradeTo(address)",
                                                    oldImplementation
                                                )
                                            );
                                            rollbackTesting.value = false;
                                            // Check rollback was effective
                                            require(oldImplementation == _getImplementation(), "ERC1967Upgrade: upgrade breaks further upgrades");
                                            // Finally reset to the new implementation and log the upgrade
                                            _setImplementation(newImplementation);
                                            emit Upgraded(newImplementation);
                                        }
                                    }
                                    /**
                                     * @dev Perform beacon upgrade with additional setup call. Note: This upgrades the address of the beacon, it does
                                     * not upgrade the implementation contained in the beacon (see {UpgradeableBeacon-_setImplementation} for that).
                                     *
                                     * Emits a {BeaconUpgraded} event.
                                     */
                                    function _upgradeBeaconToAndCall(address newBeacon, bytes memory data, bool forceCall) internal {
                                        _setBeacon(newBeacon);
                                        emit BeaconUpgraded(newBeacon);
                                        if (data.length > 0 || forceCall) {
                                            Address.functionDelegateCall(IBeacon(newBeacon).implementation(), data);
                                        }
                                    }
                                    /**
                                     * @dev Storage slot with the admin of the contract.
                                     * This is the keccak-256 hash of "eip1967.proxy.admin" subtracted by 1, and is
                                     * validated in the constructor.
                                     */
                                    bytes32 internal constant _ADMIN_SLOT = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;
                                    /**
                                     * @dev Emitted when the admin account has changed.
                                     */
                                    event AdminChanged(address previousAdmin, address newAdmin);
                                    /**
                                     * @dev Returns the current admin.
                                     */
                                    function _getAdmin() internal view returns (address) {
                                        return StorageSlot.getAddressSlot(_ADMIN_SLOT).value;
                                    }
                                    /**
                                     * @dev Stores a new address in the EIP1967 admin slot.
                                     */
                                    function _setAdmin(address newAdmin) private {
                                        require(newAdmin != address(0), "ERC1967: new admin is the zero address");
                                        StorageSlot.getAddressSlot(_ADMIN_SLOT).value = newAdmin;
                                    }
                                    /**
                                     * @dev Changes the admin of the proxy.
                                     *
                                     * Emits an {AdminChanged} event.
                                     */
                                    function _changeAdmin(address newAdmin) internal {
                                        emit AdminChanged(_getAdmin(), newAdmin);
                                        _setAdmin(newAdmin);
                                    }
                                    /**
                                     * @dev The storage slot of the UpgradeableBeacon contract which defines the implementation for this proxy.
                                     * This is bytes32(uint256(keccak256('eip1967.proxy.beacon')) - 1)) and is validated in the constructor.
                                     */
                                    bytes32 internal constant _BEACON_SLOT = 0xa3f0ad74e5423aebfd80d3ef4346578335a9a72aeaee59ff6cb3582b35133d50;
                                    /**
                                     * @dev Emitted when the beacon is upgraded.
                                     */
                                    event BeaconUpgraded(address indexed beacon);
                                    /**
                                     * @dev Returns the current beacon.
                                     */
                                    function _getBeacon() internal view returns (address) {
                                        return StorageSlot.getAddressSlot(_BEACON_SLOT).value;
                                    }
                                    /**
                                     * @dev Stores a new beacon in the EIP1967 beacon slot.
                                     */
                                    function _setBeacon(address newBeacon) private {
                                        require(
                                            Address.isContract(newBeacon),
                                            "ERC1967: new beacon is not a contract"
                                        );
                                        require(
                                            Address.isContract(IBeacon(newBeacon).implementation()),
                                            "ERC1967: beacon implementation is not a contract"
                                        );
                                        StorageSlot.getAddressSlot(_BEACON_SLOT).value = newBeacon;
                                    }
                                }
                                // SPDX-License-Identifier: MIT
                                pragma solidity ^0.8.0;
                                /**
                                 * @dev This is the interface that {BeaconProxy} expects of its beacon.
                                 */
                                interface IBeacon {
                                    /**
                                     * @dev Must return an address that can be used as a delegate call target.
                                     *
                                     * {BeaconProxy} will check that this address is a contract.
                                     */
                                    function implementation() external view returns (address);
                                }
                                // SPDX-License-Identifier: MIT
                                pragma solidity ^0.8.0;
                                /**
                                 * @dev Collection of functions related to the address type
                                 */
                                library Address {
                                    /**
                                     * @dev Returns true if `account` is a contract.
                                     *
                                     * [IMPORTANT]
                                     * ====
                                     * It is unsafe to assume that an address for which this function returns
                                     * false is an externally-owned account (EOA) and not a contract.
                                     *
                                     * Among others, `isContract` will return false for the following
                                     * types of addresses:
                                     *
                                     *  - an externally-owned account
                                     *  - a contract in construction
                                     *  - an address where a contract will be created
                                     *  - an address where a contract lived, but was destroyed
                                     * ====
                                     */
                                    function isContract(address account) internal view returns (bool) {
                                        // This method relies on extcodesize, which returns 0 for contracts in
                                        // construction, since the code is only stored at the end of the
                                        // constructor execution.
                                        uint256 size;
                                        // solhint-disable-next-line no-inline-assembly
                                        assembly { size := extcodesize(account) }
                                        return size > 0;
                                    }
                                    /**
                                     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
                                     * `recipient`, forwarding all available gas and reverting on errors.
                                     *
                                     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
                                     * of certain opcodes, possibly making contracts go over the 2300 gas limit
                                     * imposed by `transfer`, making them unable to receive funds via
                                     * `transfer`. {sendValue} removes this limitation.
                                     *
                                     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
                                     *
                                     * IMPORTANT: because control is transferred to `recipient`, care must be
                                     * taken to not create reentrancy vulnerabilities. Consider using
                                     * {ReentrancyGuard} or the
                                     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
                                     */
                                    function sendValue(address payable recipient, uint256 amount) internal {
                                        require(address(this).balance >= amount, "Address: insufficient balance");
                                        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
                                        (bool success, ) = recipient.call{ value: amount }("");
                                        require(success, "Address: unable to send value, recipient may have reverted");
                                    }
                                    /**
                                     * @dev Performs a Solidity function call using a low level `call`. A
                                     * plain`call` is an unsafe replacement for a function call: use this
                                     * function instead.
                                     *
                                     * If `target` reverts with a revert reason, it is bubbled up by this
                                     * function (like regular Solidity function calls).
                                     *
                                     * Returns the raw returned data. To convert to the expected return value,
                                     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
                                     *
                                     * Requirements:
                                     *
                                     * - `target` must be a contract.
                                     * - calling `target` with `data` must not revert.
                                     *
                                     * _Available since v3.1._
                                     */
                                    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
                                      return functionCall(target, data, "Address: low-level call failed");
                                    }
                                    /**
                                     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
                                     * `errorMessage` as a fallback revert reason when `target` reverts.
                                     *
                                     * _Available since v3.1._
                                     */
                                    function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
                                        return functionCallWithValue(target, data, 0, errorMessage);
                                    }
                                    /**
                                     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                                     * but also transferring `value` wei to `target`.
                                     *
                                     * Requirements:
                                     *
                                     * - the calling contract must have an ETH balance of at least `value`.
                                     * - the called Solidity function must be `payable`.
                                     *
                                     * _Available since v3.1._
                                     */
                                    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
                                        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
                                    }
                                    /**
                                     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
                                     * with `errorMessage` as a fallback revert reason when `target` reverts.
                                     *
                                     * _Available since v3.1._
                                     */
                                    function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
                                        require(address(this).balance >= value, "Address: insufficient balance for call");
                                        require(isContract(target), "Address: call to non-contract");
                                        // solhint-disable-next-line avoid-low-level-calls
                                        (bool success, bytes memory returndata) = target.call{ value: value }(data);
                                        return _verifyCallResult(success, returndata, errorMessage);
                                    }
                                    /**
                                     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                                     * but performing a static call.
                                     *
                                     * _Available since v3.3._
                                     */
                                    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
                                        return functionStaticCall(target, data, "Address: low-level static call failed");
                                    }
                                    /**
                                     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                                     * but performing a static call.
                                     *
                                     * _Available since v3.3._
                                     */
                                    function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
                                        require(isContract(target), "Address: static call to non-contract");
                                        // solhint-disable-next-line avoid-low-level-calls
                                        (bool success, bytes memory returndata) = target.staticcall(data);
                                        return _verifyCallResult(success, returndata, errorMessage);
                                    }
                                    /**
                                     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
                                     * but performing a delegate call.
                                     *
                                     * _Available since v3.4._
                                     */
                                    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
                                        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
                                    }
                                    /**
                                     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
                                     * but performing a delegate call.
                                     *
                                     * _Available since v3.4._
                                     */
                                    function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
                                        require(isContract(target), "Address: delegate call to non-contract");
                                        // solhint-disable-next-line avoid-low-level-calls
                                        (bool success, bytes memory returndata) = target.delegatecall(data);
                                        return _verifyCallResult(success, returndata, errorMessage);
                                    }
                                    function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
                                        if (success) {
                                            return returndata;
                                        } else {
                                            // Look for revert reason and bubble it up if present
                                            if (returndata.length > 0) {
                                                // The easiest way to bubble the revert reason is using memory via assembly
                                                // solhint-disable-next-line no-inline-assembly
                                                assembly {
                                                    let returndata_size := mload(returndata)
                                                    revert(add(32, returndata), returndata_size)
                                                }
                                            } else {
                                                revert(errorMessage);
                                            }
                                        }
                                    }
                                }
                                // SPDX-License-Identifier: MIT
                                pragma solidity ^0.8.0;
                                /**
                                 * @dev Library for reading and writing primitive types to specific storage slots.
                                 *
                                 * Storage slots are often used to avoid storage conflict when dealing with upgradeable contracts.
                                 * This library helps with reading and writing to such slots without the need for inline assembly.
                                 *
                                 * The functions in this library return Slot structs that contain a `value` member that can be used to read or write.
                                 *
                                 * Example usage to set ERC1967 implementation slot:
                                 * ```
                                 * contract ERC1967 {
                                 *     bytes32 internal constant _IMPLEMENTATION_SLOT = 0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;
                                 *
                                 *     function _getImplementation() internal view returns (address) {
                                 *         return StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value;
                                 *     }
                                 *
                                 *     function _setImplementation(address newImplementation) internal {
                                 *         require(Address.isContract(newImplementation), "ERC1967: new implementation is not a contract");
                                 *         StorageSlot.getAddressSlot(_IMPLEMENTATION_SLOT).value = newImplementation;
                                 *     }
                                 * }
                                 * ```
                                 *
                                 * _Available since v4.1 for `address`, `bool`, `bytes32`, and `uint256`._
                                 */
                                library StorageSlot {
                                    struct AddressSlot {
                                        address value;
                                    }
                                    struct BooleanSlot {
                                        bool value;
                                    }
                                    struct Bytes32Slot {
                                        bytes32 value;
                                    }
                                    struct Uint256Slot {
                                        uint256 value;
                                    }
                                    /**
                                     * @dev Returns an `AddressSlot` with member `value` located at `slot`.
                                     */
                                    function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
                                        assembly {
                                            r.slot := slot
                                        }
                                    }
                                    /**
                                     * @dev Returns an `BooleanSlot` with member `value` located at `slot`.
                                     */
                                    function getBooleanSlot(bytes32 slot) internal pure returns (BooleanSlot storage r) {
                                        assembly {
                                            r.slot := slot
                                        }
                                    }
                                    /**
                                     * @dev Returns an `Bytes32Slot` with member `value` located at `slot`.
                                     */
                                    function getBytes32Slot(bytes32 slot) internal pure returns (Bytes32Slot storage r) {
                                        assembly {
                                            r.slot := slot
                                        }
                                    }
                                    /**
                                     * @dev Returns an `Uint256Slot` with member `value` located at `slot`.
                                     */
                                    function getUint256Slot(bytes32 slot) internal pure returns (Uint256Slot storage r) {
                                        assembly {
                                            r.slot := slot
                                        }
                                    }
                                }