util/promlint/promlint.go
func (p *problems) Add(mf dto.MetricFamily, text string) {
	*p = append(*p, Problem{
		Metric: mf.GetName(),
		Text:   text,
	})
}
func (p *problems) Add(mf dto.MetricFamily, text string) {
	*p = append(*p, Problem{
		Metric: mf.GetName(),
		Text:   text,
	})
}
// Add appends a new Problem to the slice for the specified metric, with
// the specified issue text.