code: public static Stream<String> getLanguageCodes() {
      return Stream.of(
          LANGUAGE_CODE_EN,
          LANGUAGE_CODE_NL,
          LANGUAGE_CODE_DE,
          LANGUAGE_CODE_ES,
          LANGUAGE_CODE_IT,
          LANGUAGE_CODE_PT,
          LANGUAGE_CODE_FR,
          LANGUAGE_CODE_XX);
    }
docs: "en": is default "xx": is a placeholder for having your own language "nl", "de", "es", "it",
  "pt", "fr": are extra languages