}
	return v.toPromName(mg.CollectorPath.metricPrefix())
}

func (mg *MetricsGroup) validate() {
	if len(mg.Descriptors) == 0 {
		panic("Descriptors must be set")
	}

	// For bools A and B, A XOR B <=> A != B.
	isExactlyOneSet := (mg.loader == nil) != (mg.bucketLoader == nil)
	if !isExactlyOneSet {
		panic("Exactly one Loader function must be set")
	}