code: func (queue *Queue) Put(payload string) error {
  	p := &Package{CreatedAt: time.Now(), Payload: payload, Queue: queue}
  	lpush := queue.redisClient.LPush(queueInputKey(queue.Name), p.getString())
  	queue.incrRate(queueInputRateKey(queue.Name), 1)
  	return lpush.Err()
  }
docs: // Put writes the payload into the input queue