code: def heartbeat(self):
          
          while self._manager.is_active and not self._stop_event.is_set():
              self._manager.heartbeat()
              _LOGGER.debug("Sent heartbeat.")
              self._stop_event.wait(timeout=self._period)
  
          _LOGGER.info("%s exiting.", _HEARTBEAT_WORKER_NAME)
docs: Periodically send heartbeats.