code: def start(self):
          
          # observers for this channel only need to wait for one value
          self._observer_params.update(dict(once=True))
          super(CurrentResourceValue, self).start()
          self._api.ensure_notifications_thread()
          self._api._mds_rpc_post(
              device_id=self.device_id,
              method='GET',
              uri=self.resource_path,
              async_id=self.async_id,
              _wrap_with_consumer=False,
          )
docs: Start the channel