code: func RegisterMetricAndTrackRateLimiterUsage(ownerName string, rateLimiter flowcontrol.RateLimiter) error {
  	if err := registerRateLimiterMetric(ownerName); err != nil {
  		return err
  	}
  	// TODO: determine how to track rate limiter saturation
  	// See discussion at https://go-review.googlesource.com/c/time/+/29958#message-4caffc11669cadd90e2da4c05122cfec50ea6a22
  	// go wait.Until(func() {
  	//   metricsLock.Lock()
  	//   defer metricsLock.Unlock()
  	//   rateLimiterMetrics[ownerName].metric.Set()
  	// }, updatePeriod, rateLimiterMetrics[ownerName].stopCh)
  	return nil
  }
docs: // RegisterMetricAndTrackRateLimiterUsage registers a metric ownerName_rate_limiter_use in prometheus to track
  // how much used rateLimiter is and starts a goroutine that updates this metric every updatePeriod