code: public ULocale[] getAvailableULocales() {
          Set<String> keys = getLocaleIdToRulesIdMap(PluralType.CARDINAL).keySet();
          ULocale[] locales = new ULocale[keys.size()];
          int n = 0;
          for (Iterator<String> iter = keys.iterator(); iter.hasNext();) {
              locales[n++] = ULocale.createCanonical(iter.next());
          }
          return locales;
      }
docs: Returns the locales for which we have plurals data. Utility for testing.