protected void updateHeight() {
			int lesserHeight = 0;
			int greaterHeight = 0;
			if (lesser != null) {
				AVLNode<T> lesserAVLNode = (AVLNode<T>) lesser;
				lesserHeight = lesserAVLNode.height;
			}
			if (greater != null) {
				AVLNode<T> greaterAVLNode = (AVLNode<T>) greater;
				greaterHeight = greaterAVLNode.height;
			}

			if (lesserHeight > greaterHeight) {
				height = lesserHeight + 1;
			} else {
				height = greaterHeight + 1;
			}
		}