code: def on_open(self, websocket):
          '''When a new websocket connection is established it creates a
          new :class:`ChatClient` and adds it to the set of clients of the
          :attr:`pubsub` handler.'''
          self.pubsub.add_client(ChatClient(websocket, self.channel)f on_open(self, websocket):
          '''When a new websocket connection is established it creates a
          new :class:`ChatClient` and adds it to the set of clients of the
          :attr:`pubsub` handler.'''
          self.pubsub.add_client(ChatClient(websocket, self.channel))
docs: When a new websocket connection is established it creates a
          new :class:`ChatClient` and adds it to the set of clients of the
          :attr:`pubsub` handler.