resolution method
Implementation
LocaleResolutionCallback resolution(
    {Locale? fallback, bool withCountry = true}) {
  return (Locale? locale, Iterable<Locale> supported) {
    return _resolve(locale, fallback, supported, withCountry);
  };
}LocaleResolutionCallback resolution(
    {Locale? fallback, bool withCountry = true}) {
  return (Locale? locale, Iterable<Locale> supported) {
    return _resolve(locale, fallback, supported, withCountry);
  };
}