return
	}
	if len(complMultipartUpload.Parts) == 0 {
		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrMissingPart), r.URL)
		return
	}

	if !sort.SliceIsSorted(complMultipartUpload.Parts, func(i, j int) bool {
		return complMultipartUpload.Parts[i].PartNumber < complMultipartUpload.Parts[j].PartNumber
	}) {
		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrInvalidPartOrder), r.URL)

}

// sortByModTime will sort versions by modtime in descending order,
// meaning index 0 will be latest version.
func (x *xlMetaV2) sortByModTime() {
	// Quick check
	if len(x.versions) <= 1 || sort.SliceIsSorted(x.versions, func(i, j int) bool {
		return x.versions[i].header.sortsBefore(x.versions[j].header)
	}) {
		return
	}

	// We should sort.
	sort.Slice(x.versions, func(i, j int) bool {