class CountryFacadeImpl implements CountryFacade {

  @Inject
  private CountryService countryService;

  @Override
  public List<ReadableCountry> getListCountryZones(Language language, MerchantStore merchantStore) {
    return getListOfCountryZones(language)
        .stream()
        .map(country -> convertToReadableCountry(country, language, merchantStore))
        .collect(Collectors.toList());
  }

  private ReadableCountry convertToReadableCountry(Country country, Language language, MerchantStore merchantStore) {
    try{
      ReadableCountryPopulator populator = new ReadableCountryPopulator();
      return populator.populate(country, new ReadableCountry(), merchantStore, language);
    } catch (ConversionException e) {
      throw new ConversionRuntimeException(e);
    }
  }

  private List<Country> getListOfCountryZones(Language language) {<FILL_FUNCTION_BODY>}
}

    try{
      return countryService.listCountryZones(language);
    } catch (ServiceException e) {
      throw new ServiceRuntimeException(e);
    }
  
<no_super_class>