contract UpgradeableProxy is Proxy {
    /**
     * @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)
        );
        _setImplementation(_logic);
        if (_data.length > 0) {
            Address.functionDelegateCall(_logic, _data);
        }
    }

    /**
     * @dev Emitted when the implementation is upgraded.
     */
    event Upgraded(address indexed implementation);

    /**
     * @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 private constant _IMPLEMENTATION_SLOT =
        0x360894a13ba1a3210667c828492db98dca3e2076cc3735a920a3ca505d382bbc;

    /**
     * @dev Returns the current implementation address.
     */
    function _implementation()
        internal
        view
        virtual
        override
        returns (address impl)
    {
        bytes32 slot = _IMPLEMENTATION_SLOT;
        // solhint-disable-next-line no-inline-assembly
        assembly {
            impl := sload(slot)
        }
    }

    /**
     * @dev Upgrades the proxy to a new implementation.
     *
     * Emits an {Upgraded} event.
     */
    function _upgradeTo(address newImplementation) internal virtual {
        _setImplementation(newImplementation);
        emit Upgraded(newImplementation);
    }

    /**
     * @dev Stores a new address in the EIP1967 implementation slot.
     */
    function _setImplementation(address newImplementation) private {
        require(
            Address.isContract(newImplementation),
            "UpgradeableProxy: new implementation is not a contract"
        );

        bytes32 slot = _IMPLEMENTATION_SLOT;

        // solhint-disable-next-line no-inline-assembly
        assembly {
            sstore(slot, newImplementation)
        }
    }
}
function _setImplementation(address newImplementation) private {
        require(
            Address.isContract(newImplementation),
            "UpgradeableProxy: new implementation is not a contract"
        );

        bytes32 slot = _IMPLEMENTATION_SLOT;

        // solhint-disable-next-line no-inline-assembly
        assembly {
            sstore(slot, newImplementation)
        }
    }
/**
 * @dev Stores a new address in the EIP1967 implementation slot.
 */