updateLangauge method Null safety
- String? lang
Set the language to use within the app for localization
Implementation
updateLangauge(String? lang) {
  if (lang == null) {
    return;
  }
  language(lang);
  // wait for a Flutter build cycle, if the settings are returned instantly
  Future.delayed(
    Duration.zero,
    () => WidgetsBinding.instance!.performReassemble(),
  );
}