code: def async_session_handler(self, signal: str) -> None:
          
          if signal == 'data':
              self.async_event_handler(self.websocket.data)
          elif signal == 'state':
              if self.async_connection_status_callback:
                  self.async_connection_status_callback(
                      self.websocket.state == 'running')
docs: Signalling from websocket.
  
             data - new data available for processing.
             state - network state has changed.