def clientConnectionLost(self, connector, reason):
        """
        Called when an established connection is lost.

        It may be useful to call connector.connect() - this will reconnect.

        @type reason: L{twisted.python.failure.Failure}
        """

        Called when an established connection is lost.

        It may be useful to call connector.connect() - this will reconnect.

        @type reason: L{twisted.python.failure.Failure}
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/internet/protocol.py