code: public static Set<Locale> getAvailableLocales() {
          Locale[] l = DecimalFormatSymbols.getAvailableLocales();
          Set<Locale> locales = new HashSet<>(l.length);
          Collections.addAll(locales, l);
          return locales;
      }
docs: Lists all the locales that are supported.
  <p>
  The locale 'en_US' will always be present.
  
  @return a Set of Locales for which localization is supported