code: func NewObserver(redisHost, redisPort, redisPassword string, redisDb int64) *Observer {
  	q := &Observer{
  		redisHost:     redisHost,
  		redisPort:     redisPort,
  		redisPassword: redisPassword,
  		redisDb:       redisDb,
  		Stats:         make(map[string]*QueueStat),
  	}
  	q.redisClient = redis.NewClient(&redis.Options{
  		Addr:     redisHost + ":" + redisPort,
  		Password: redisPassword,
  		DB:       redisDb,
  	})
  	return q
  }
docs: // NewObserver returns an Oberserver to monitor different statistics from redis