@Override
	public Collection<V> values() {

		ArrayList<MapEntry<K, V>> ar = new ArrayList<MapEntry<K, V>>();
		tree.postOrder(ar);
		ArrayList<V> v = new ArrayList<V>();
		for (MapEntry<K, V> e : ar) {
			v.add(e.getValue());
		}

		return (Collection<V>) v;
	}