code: func (ctl *Controller) requestJobStateUpdate(c context.Context, jobID JobID, shardID int64) error {
  	return ctl.tq().AddTask(c, &tq.Task{
  		Title: fmt.Sprintf("notify:job-%d-shard-%d", jobID, shardID),
  		Payload: &tasks.RequestJobStateUpdate{
  			JobId:   int64(jobID),
  			ShardId: shardID,
  		},
  	})
  }
docs: // requestJobStateUpdate submits RequestJobStateUpdate task, which eventually
  // causes updateJobStateHandler to execute.