for _, label := range md.VariableLabels {
		md.labelSet[label] = struct{}{}
	}
	return md.labelSet
}

func (md *MetricDescriptor) toPromName(namePrefix string) string {
	return prometheus.BuildFQName(namePrefix, "", string(md.Name))
}

func (md *MetricDescriptor) toPromDesc(namePrefix string, extraLabels map[string]string) *prometheus.Desc {
	return prometheus.NewDesc(
		md.toPromName(namePrefix),
		md.Help,