code: public static Map<String, String> readPhoneCountryCodes(final Locale plocale) {
      final PhoneCountryCodeConstants phoneCountryCodes = GWT.create(PhoneCountryCodeConstants.class);
      return phoneCountryCodes.phoneCountryCodes();
    }
docs: read phone country codes and country iso codes.
  
  @return map of phone country code and country iso code