// mergeV1 is used to migrate data usage cache from sizeHistogramV1 to
// sizeHistogram
func (h *sizeHistogram) mergeV1(v sizeHistogramV1) {
	var oidx, nidx int
	for oidx < len(v) {
		intOld, intNew := ObjectsHistogramIntervalsV1[oidx], ObjectsHistogramIntervals[nidx]
		// skip intervals that aren't common to both histograms
		if intOld.start != intNew.start || intOld.end != intNew.end {
			nidx++
			continue
		}