class MultiMap extends HashMap<String, List<V>> {

    public void add(String name, V value) {
        List<V> lo = get(name);
        if (lo == null) {
            lo = new ArrayList<>();
        }
        lo.add(value);
        super.put(name, lo);
    }

    public  MultiMap();
    public  MultiMap(Map<String, List<V>> map);
    public  MultiMap(MultiMap<V> map);

}