docs: def on_stop(self):
          """
          stop the service
          """
          LOGGER.debug("natsd.Service.on_stop")
          self.is_started = False
          try:
              next(self.nc.unsubscribe(self.serviceQS))
          except StopIteration as e:
              pass
          try:
              next(self.nc.close())
          except StopIteration as e:
              pass
          try:
              for task in asyncio.Task.all_tasks(self.loop):
                  task.cancel()
              self.loop.stop()
              while self.loop.is_running():
                  time.sleep(1)
              self.loop.close()
          except Exception as e:
              LOGGER.debug("natsd.Service.on_stop - Exception aio clean up : "
                           + traceback.format_exc())