def unhandledControlSequence(seq):
        """
        Called when an unsupported control sequence is received.

        @type seq: L{str}
        @param seq: The whole control sequence which could not be interpreted.
        """

        Called when an unsupported control sequence is received.

        @type seq: L{str}
        @param seq: The whole control sequence which could not be interpreted.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/conch/insults/insults.py