code: func AddJitter(duration time.Duration, jitter time.Duration) time.Duration {
  	var randJitter int64
  	if jitter.Nanoseconds() == 0 {
  		randJitter = 0
  	} else {
  		randJitter = rand.Int63n(jitter.Nanoseconds())
  	}
  	return time.Duration(duration.Nanoseconds() + randJitter)
  }
docs: // AddJitter adds an amount of jitter between 0 and the given jitter to the
  // given duration