Method peekNode

ZezeJava/ZezeJava/src/main/java/Zeze/Collections/Queue.java:237–247

@return 头节点，null if empty

()

	 * @return 头节点，null if empty
	 */
	public BQueueNode peekNode() {
		var root = getRoot();
		if (root == null)
			return null;

		var headKey = root.getHeadNodeKey();
		if (headKey.getNodeId() == 0)
			return null;

		return getNode(headKey);
	}

	/**
	 * 删除并返回头节点中的首个值