code: def process_groupchat_message(self,stanza):
          
          fr=stanza.get_from()
          user=self.get_user(fr,True)
          s=stanza.get_subject()
          if s:
              self.subject=s
              self.handler.subject_changed(user,stanza)
          else:
              self.handler.message_received(user,stanza)
docs: Process <message type="groupchat"/> received from the room.
  
          :Parameters:
              - `stanza`: the stanza received.
          :Types:
              - `stanza`: `Message`