func mustGetUUIDBytes() []byte {
	u, err := uuid.NewRandom()
	if err != nil {
		logger.CriticalIf(GlobalContext, err)
	}
	return u[:]
}

// Create an s3 compatible MD5sum for complete multipart transaction.
func getCompleteMultipartMD5(parts []CompletePart) string {
	var finalMD5Bytes []byte
	for _, part := range parts {
		md5Bytes, err := hex.DecodeString(canonicalizeETag(part.ETag))
		if err != nil {