class ItemValuesMap implements Serializable {

    public String concatMultiStringsWithBlank(String... keys) {
        StringBuilder result = new StringBuilder();
        for (String key : keys) {
            if (has(key)) {
                result.append(getAsString(key)).append(" ");
            }
        }
        return result.toString().trim();
    }

    public  ItemValuesMap();
    public  ItemValuesMap(Map<String, Object> values);

}