code: async def on_raw_topic(self, message):
          
          setter, settermeta = self._parse_user(message.source)
          target, topic = message.params
  
          self._sync_user(setter, settermeta)
  
          # Update topic in our own channel list.
          if self.in_channel(target):
              self.channels[target]['topic'] = topic
              self.channels[target]['topic_by'] = setter
              self.channels[target]['topic_set'] = datetime.datetime.now()
  
          await self.on_topic_change(target, topic, setter)
docs: TOPIC command.