如何将节点树的数据转换为有序的ArrayList？

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class Node {
    private int value;
    private List<Node> children;

    // 构造函数和其他方法

    public List<Integer> convertToArrayList() {
        List<Integer> result = new ArrayList<>();
        dfs(this, result);
        Collections.sort(result);
        return result;
    }

    private void dfs(Node node, List<Integer> list) {
        if (node == null) {
            return;
        }
        list.add(node.getValue());
        for (Node child : node.getChildren()) {
            dfs(child, list);
        }
    }
}