code: def join(self, event):
          
  
          try:
              channel_uuid = event.data
              user_uuid = event.user.uuid
  
              if channel_uuid in self.chat_channels:
                  self.log('User joins a known channel', lvl=debug)
                  if user_uuid in self.chat_channels[channel_uuid].users:
                      self.log('User already joined', lvl=warn)
                  else:
                      self.chat_channels[channel_uuid].users.append(user_uuid)
                      self.chat_channels[channel_uuid].save()
                      packet = {
                          'component': 'hfos.chat.host',
                          'action': 'join',
                          'data': channel_uuid
                      }
                      self.fireEvent(send(event.client.uuid, packet))
              else:
                  self.log('Request to join unavailable channel', lvl=warn)
          except Exception as e:
              self.log('Join error:', e, type(e), exc=True, lvl=error)
docs: Chat event handler for incoming events
          :param event: say-event with incoming chat message