class PersistentSet implements Set<E> {

    @Override
    public boolean addAll(Collection<? extends E> c) {
        checkNotNull(c, "The collection to be added cannot be null.");
        boolean changed = false;
        for (Object item : c) {
            changed = items.add(serializer.encode(item)) || changed;
        }
        return changed;
    }

    public  PersistentSet(org.onosproject.store.service.Serializer serializer, DB database, String name);

}