code: func (sp *StoragePlugin) Stop(ctx context.Context) {
  	sp.stopOnce.Do(func() {
  		sp.server.Stop()
  		log.Info("stopped")
  	})
  }
docs: // Stop stops the gRPC server. It immediately closes all open
  // connections and listeners.
  // It cancels all active RPCs on the server side and the corresponding
  // pending RPCs on the client side will get notified by connection
  // errors.