def list(self, channels):
        """
        Send a group of LIST response lines

        @type channel: C{list} of C{(str, int, str)}
        @param channel: Information about the channels being sent:
        their name, the number of participants, and their topic.
        """
        for (name, size, topic) in channels:
            self.sendMessage(irc.RPL_LIST, name, str(size), ":" + topic)
        self.sendMessage(irc.RPL_LISTEND, ":End of /LIST")

        Send a group of LIST response lines

        @type channel: C{list} of C{(str, int, str)}
        @param channel: Information about the channels being sent:
        their name, the number of participants, and their topic.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/words/service.py