r := &dto.MetricFamily{}
	r.Name = mf.Name
	r.Help = mf.Help
	r.Type = mf.Type
	r.Metric = make([]*dto.Metric, len(mf.Metric))
	for i, m := range mf.Metric {
		r.Metric[i] = deepCopyMetric(m)
	}
	return r
}

func deepCopyMetric(m *dto.Metric) *dto.Metric {
	r := &dto.Metric{}
	r.Label = make([]*dto.LabelPair, len(m.Label))
	for i, lp := range m.Label {
		r.Label[i] = deepCopyLabelPair(lp)
	}