class Bag extends AbstractCollection<T> implements Serializable {

    public int count(T item) {
        Validate.notNull(item, "item must not be null");
        Integer count = map.get(item);
        return count == null ? 0 : count;
    }

    public  Bag();
    public  Bag(Map<? extends T, ? extends Integer> map);
    private  Bag(Map<T, Integer> map, int size);
    public  Bag(Iterable<? extends T> iterable);

}