def loseConnection(self):
        """
        Lose the connection to the other side, sending a
        DISCONNECT_CONNECTION_LOST message.
        """
        self.sendDisconnect(DISCONNECT_CONNECTION_LOST,
                            b"user closed connection")

        Lose the connection to the other side, sending a
        DISCONNECT_CONNECTION_LOST message.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/conch/ssh/transport.py