Method insertBefore

java/Chapter 2/Question2_5/QuestionB.java:54–61

(LinkedListNode list, int data)

	}
	
	private static LinkedListNode insertBefore(LinkedListNode list, int data) {
		LinkedListNode node = new LinkedListNode(data, null, null);
		if (list != null) {
			list.prev = node;
			node.next = list;
		}
		return node;
	}
	
	public static int linkedListToInt(LinkedListNode node) {
		int value = 0;