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();
        }
    }
/**
 * @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.
 */
function _implementation() internal view virtual override returns (address impl) {
    return ERC1967Upgrade._getImplementation();
}

/**
 * @dev Returns the current implementation address.
 */