val := r.Trailer.Get(t.Key())
		if val != "" {
			w.Header().Set(t.Key(), val)
		}
		return
	}
	w.Header().Set(t.Key(), s)
}

// AddChecksumHeader will transfer any checksum value that has been checked.
func AddChecksumHeader(w http.ResponseWriter, c map[string]string) {
	for k, v := range c {
		if k == xhttp.AmzChecksumType {
			w.Header().Set(xhttp.AmzChecksumType, v)
			continue
		}

		if lc, err := globalLifecycleSys.Get(objInfo.Bucket); err == nil && !del {
			lc.SetPredictionHeaders(w, objInfo.ToLifecycleOpts())
		}
	}
	cs, _ := objInfo.decryptChecksums(0, h)
	hash.AddChecksumHeader(w, cs)
}

func deleteObjectVersions(ctx context.Context, o ObjectLayer, bucket string, toDel []ObjectToDelete, lcEvent []lifecycle.Event) {
	for remaining := toDel; len(remaining) > 0; toDel = remaining {