def lookupChannel(self, channelType, windowSize, maxPacket, data):
        """
        The server wants us to return a channel.  If the requested channel is
        our TestChannel, return it, otherwise return None.
        """
        if channelType == TestChannel.name:
            return TestChannel(remoteWindow=windowSize,
                    remoteMaxPacket=maxPacket,
                    data=data, avatar=self)
        elif channelType == b"conch-error-args":
            # Raise a ConchError with backwards arguments to make sure the
            # connection fixes it for us.  This case should be deprecated and
            # deleted eventually, but only after all of Conch gets the argument
            # order right.
            raise error.ConchError(
                self._ARGS_ERROR_CODE, "error args in wrong order")

        The server wants us to return a channel.  If the requested channel is
        our TestChannel, return it, otherwise return None.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/conch/test/test_connection.py