code: func pubSubPull(c *router.Context) {
  	if !appengine.IsDevAppServer() {
  		replyError(c.Context, c.Writer, errors.New("not a dev server"))
  		return
  	}
  	processPubSubRequest(c.Context, c.Writer, c.Request, func(c context.Context, srv authService, serviceURL string) (*service.Notification, error) {
  		return srv.PullPubSub(c, subscriptionName(c, serviceURL))
  	})
  }
docs: // pubSubPull is HTTP handler that pulls PubSub messages from AuthDB change
  // notification topic.
  //
  // Used only on dev server for manual testing. Prod services use push-based
  // delivery.