Method concat

java/Chapter 17/Question17_13/QuestionC.java:84–87

(BiNode x, BiNode y)

	}
	
	public static void concat(BiNode x, BiNode y) {
		x.node2 = y;
		y.node1 = x;
	}
	
	public static void main(String[] args) {
		BiNode root = createTree();