code: func (e *Enqueuer) EnqueueUniqueInByKey(jobName string, secondsFromNow int64, args map[string]interface{}, keyMap map[string]interface{}) (*ScheduledJob, error) {
  	enqueue, job, err := e.uniqueJobHelper(jobName, args, keyMap)
  	if err != nil {
  		return nil, err
  	}
  
  	scheduledJob := &ScheduledJob{
  		RunAt: nowEpochSeconds() + secondsFromNow,
  		Job:   job,
  	}
  
  	res, err := enqueue(&scheduledJob.RunAt)
  	if res == "ok" && err == nil {
  		return scheduledJob, nil
  	}
  	return nil, err
  }
docs: // EnqueueUniqueInByKey enqueues a job in the scheduled job queue that is unique on specified key for execution in secondsFromNow seconds. See EnqueueUnique for the semantics of unique jobs.
  // Subsequent calls with same key will update arguments