class PersistentSet implements Set<E> {

    @Override
    public boolean removeAll(Collection<?> c) {
        boolean changed = false;
        for (Object item : c) {
            changed = items.remove(serializer.encode(item)) || changed;
        }
        return changed;
    }

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

}