class RedBlackTree implements Iterable<RedBlackEntry<K, V>> {

	public V remove(K key) {

		RedBlackEntry<K, V> node = getNode(key);
		if (node == null) {
			return null;
		}
		V value = node.value;
		deleteEntry(node);
		return value;
	}

	public  RedBlackTree();

}