code: def start_notifications(self):
          
          with self._notifications_lock:
              if self.has_active_notification_thread:
                  return
              api = self._get_api(mds.NotificationsApi)
              self._notifications_thread = NotificationsThread(
                  self._db,
                  self._queues,
                  b64decode=self.b64decode,
                  notifications_api=api,
                  subscription_manager=self.subscribe,
              )
              self._notifications_thread.daemon = True
              self._notifications_thread.start()
docs: Start the notifications thread.
  
          If an external callback is not set up (using `update_webhook`) then
          calling this function is mandatory to get or set resource.
  
          .. code-block:: python
  
              >>> api.start_notifications()
              >>> print(api.get_resource_value(device, path))
              Some value
              >>> api.stop_notifications()
  
          :returns: void