// metrics group.
func (mg *MetricsGroup) IsBucketMetricsGroup() bool {
	return mg.bucketLoader != nil
}

// Describe - implements prometheus.Collector interface.
func (mg *MetricsGroup) Describe(ch chan<- *prometheus.Desc) {
	for _, desc := range mg.Descriptors {
		ch <- desc.toPromDesc(mg.CollectorPath.metricPrefix(), mg.ExtraLabels)
	}
}