code: func (e *Enqueuer) EnqueueUniqueByKey(jobName string, args map[string]interface{}, keyMap map[string]interface{}) (*Job, error) {
  	enqueue, job, err := e.uniqueJobHelper(jobName, args, keyMap)
  	if err != nil {
  		return nil, err
  	}
  
  	res, err := enqueue(nil)
  
  	if res == "ok" && err == nil {
  		return job, nil
  	}
  	return nil, err
  }
docs: // EnqueueUniqueByKey enqueues a job unless a job is already enqueued with the same name and key, updating arguments.
  // The already-enqueued job can be in the normal work queue or in the scheduled job queue.
  // Once a worker begins processing a job, another job with the same name and key can be enqueued again.
  // Any failed jobs in the retry queue or dead queue don't count against the uniqueness -- so if a job fails and is retried, two unique jobs with the same name and arguments can be enqueued at once.
  // In order to add robustness to the system, jobs are only unique for 24 hours after they're enqueued. This is mostly relevant for scheduled jobs.
  // EnqueueUniqueByKey returns the job if it was enqueued and nil if it wasn't