public static String formatLocalizedErrorMessage(Message localizedErrorMessage, Locale locale) {
    var bundle = ResourceBundle.getBundle(BUNDLE, locale);
    var localizedMessage = bundle.getString(localizedErrorMessage.messageKey());

    var key = localizedErrorMessage.messageKey();
    if (!key.isBlank()) {
      localizedMessage = localizedMessage.formatted((Object[]) localizedErrorMessage.args());
    }
    return localizedMessage;
  }
@Test
  void tes_negotiatePreferredLocales_simpleError() {

    var errorMessage = new Message("error.serverError");
    var locale = Locale.GERMANY;

    var result = LocaleUtils.formatLocalizedErrorMessage(errorMessage, locale);

    assertEquals("Ohh nein! Unerwarteter Serverfehler. Bitte versuchen Sie es erneut.", result);
  }