public function getLanguageUid(int $default = null): int {
    $languageUid = $default ?: 0;

    if (TYPO3_MODE === 'FE') {
      if (isset($GLOBALS['TSFE']->sys_language_uid)) {
        $languageUid = $GLOBALS['TSFE']->sys_language_uid;
      }
    } elseif (is_object($GLOBALS['LANG'])) {
      if (isset($GLOBALS['LANG']->sys_language_uid)) {
        $languageUid = $GLOBALS['LANG']->sys_language_uid;
      }
    }

    return $languageUid;
  }