public static void validateCity(City city) throws TechnicalException {
        if (city == null) {
            throw new TechnicalException(MSG_ERR_NULL_ENTITY);
        }
        if ( ! isStringValid(city.getName(), NAME_SIZE)) {
            throw new TechnicalException(NAME_ERROR_MSG);
        }
        if ( ! isStringValid(city.getPicture(), PICTURE_SIZE)) {
            throw new TechnicalException(PICTURE_ERROR_MSG);
        }
        if ( ! isSelectedElem(city.getCountry().getIdCountry())) {
            throw new TechnicalException(SELECT_COUNTRY_ERROR_MSG);
        }
    }