if ($fallbackLanguage !== '' && $language !== $fallbackLanguage) {
            $messages = $this->loadFallbackMessages($category, $fallbackLanguage, $messages, $messageFile);
        } elseif ($fallbackSourceLanguage !== '' && $language === $fallbackSourceLanguage) {
            $messages = $this->loadFallbackMessages($category, $this->sourceLanguage, $messages, $messageFile);
        } elseif ($messages === null) {