mg.ExtraLabels)
	for _, metric := range promMetrics {
		ch <- metric
	}
}

// LockAndSetBuckets - locks the buckets and sets the given buckets. It returns
// a function to unlock the buckets.
func (mg *MetricsGroup) LockAndSetBuckets(buckets []string) func() {
	mg.bucketsLock.Lock()
	mg.buckets = buckets
	return func() {
		mg.bucketsLock.Unlock()
	}
}