def doWrite():
        """
        Some data can be written to your descriptor.

        @return: If an error is encountered which causes the descriptor to
            no longer be valid, a L{Failure} should be returned.  Otherwise,
            L{None}.
        """

        Some data can be written to your descriptor.

        @return: If an error is encountered which causes the descriptor to
            no longer be valid, a L{Failure} should be returned.  Otherwise,
            L{None}.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/internet/interfaces.py