bucketLoader:  loader,
	}
	mg.validate()
	return mg
}

// AddExtraLabels - adds extra (constant) label KV pairs to the metrics group.
// This is a helper to initialize the `ExtraLabels` field. The argument is a
// list of ordered label name and value pairs.
func (mg *MetricsGroup) AddExtraLabels(labels ...string) {
	if len(labels)%2 != 0 {
		panic("Labels must be an ordered list of name value pairs")

	mgMap := make(map[collectorPath]*MetricsGroup)
	bucketMGMap := make(map[collectorPath]*MetricsGroup)
	for _, mg := range allMetricGroups {
		if !strings.HasPrefix(string(mg.CollectorPath), clusterBasePath) {
			mg.AddExtraLabels(
				serverName, globalLocalNodeName,
				// poolIndex, strconv.Itoa(globalLocalPoolIdx),
			)
		}
		mg.SetCache(metricsCache)
		if mg.IsBucketMetricsGroup() {
			bucketMGMap[mg.CollectorPath] = mg