def topic(self, channel, topic=None):
        """
        Attempt to set the topic of the given channel, or ask what it is.

        If topic is None, then I sent a topic query instead of trying to set the
        topic. The server should respond with a TOPIC message containing the
        current topic of the given channel.

        @type channel: C{str}
        @param channel: The name of the channel to change the topic on. If it
            has no prefix, C{'#'} will be prepended to it.
        @type topic: C{str}
        @param topic: If specified, what to set the topic to.
        """
        # << TOPIC #xtestx :fff
        if channel[0] not in CHANNEL_PREFIXES:
            channel = '#' + channel
        if topic != None:
            self.sendLine("TOPIC %s :%s" % (channel, topic))
        else:
            self.sendLine("TOPIC %s" % (channel,))
dataset/ETHPy150Open kuri65536/python-for-android/python-modules/twisted/twisted/words/protocols/irc.py/IRCClient.topic/original