// if set, it lowercases the `api` label values.
func getHistogramMetrics(hist *prometheus.HistogramVec, desc MetricDescription, toLowerAPILabels, limitBuckets bool) []MetricV2 {
	ch := make(chan prometheus.Metric)
	go func() {
		defer xioutil.SafeClose(ch)
		// Collects prometheus metrics from hist and sends it over ch
		hist.Collect(ch)
	}()

	// Converts metrics received into internal []Metric type