contract Ownable {

    /// @notice Storage position of the masters address (keccak256('eip1967.proxy.admin') - 1)
    bytes32 private constant masterPosition = 0xb53127684a568b3173ae13b9f8a6016e243e63b6e8ee1178d6a717850b5d6103;

    /// @notice Contract constructor
    /// @dev Sets msg sender address as masters address
    /// @param masterAddress Master address
    constructor(address masterAddress) public {
        setMaster(masterAddress);
    }

    /// @notice Check if specified address is master
    /// @param _address Address to check
    function requireMaster(address _address) internal view {
        require(_address == getMaster(), "oro11"); // oro11 - only by master
    }

    /// @notice Returns contract masters address
    /// @return Masters address
    function getMaster() public view returns (address master) {
        bytes32 position = masterPosition;
        assembly {
            master := sload(position)
        }
    }

    /// @notice Sets new masters address
    /// @param _newMaster New masters address
    function setMaster(address _newMaster) internal {
        bytes32 position = masterPosition;
        assembly {
            sstore(position, _newMaster)
        }
    }

    /// @notice Transfer mastership of the contract to new master
    /// @param _newMaster New masters address
    function transferMastership(address _newMaster) external {
        requireMaster(msg.sender);
        require(_newMaster != address(0), "otp11"); // otp11 - new masters address can't be zero address
        setMaster(_newMaster);
    }

}
/// @title Ownable Contract
/// @author Matter Labs
/// @author ZKSwap L2 Labs
function setMaster(address _newMaster) internal {
        bytes32 position = masterPosition;
        assembly {
            sstore(position, _newMaster)
        }
    }
/// @notice Sets new masters address
/// @param _newMaster New masters address