Javascript 尝试实现DFS而不是BFS

我已经实现了BFS来搜索芒果卖家。不过，我现在就要尝试DFS了，但发现有点难。我尝试使用pop（）和unshift（）来代替，但仍然得到相同的输出。我希望看到不同的产出。如您所见，为了帮助自己，我对代码进行了注释

//We define a graph
class Node {
    constructor() {
        //hash map
        this.connections = new Map()
        //attributes
        this.attributes = new Map()
    }
}

class Graph {
    constructor() {
        //get nodes
        this.nodes = new Node()
    }
    
    //Add node
    addNode(node) {
        this.nodes.connections.set(node, [])
        this.nodes.attributes.set(node, [])
    }
    
    addNodeAttribute(node, attribute) {
        //set a node attribute
        this.nodes.attributes.get(node).push(attribute)
    }

    //Create an edge
    addEdge(source, destination) {
        //if A is friend with B, b is friends with A //undirected 
        this.nodes.connections.get(source).push(destination)
        this.nodes.connections.get(destination).push(source)
    }
    breadthFirstSearch(startingNode) {
        let visitedNodes = []
        let queue = []

        visitedNodes[startingNode] = true
        queue.push(startingNode)

        while (queue.length > 0) {
            const currentNode = queue.shift() //takes the first element
            const connections = this.nodes.connections.get(currentNode)
            
            if (this.nodes.attributes.get(currentNode) == "Mango") {
                return currentNode
            }
            for (let node of connections) {
                if(!visitedNodes[node]) { //if not visited
                    visitedNodes[node] = true //then true
                    queue.push(node) //push node
                }
            }
        }
        return "no mango sellers"
    }
}

let graph = new Graph()

//Create nodes
graph.addNode("Nicolai")
graph.addNode("Alice")
graph.addNode("Claire")
graph.addNode("Peggy")
graph.addNode("Bob")
graph.addNode("Anuj")
graph.addNode("Jonny")
graph.addNode("Thom")

//selling mangoer
graph.addNodeAttribute("Thom", "Mango")

//add edeges
graph.addEdge("Nicolai", "Bob")
graph.addEdge("Nicolai", "Claire")
graph.addEdge("Nicolai", "Alice")
graph.addEdge("Alice", "Peggy")
graph.addEdge("Bob", "Peggy" )
graph.addEdge("Bob", "Anuj")
graph.addEdge("Claire", "Thom")
graph.addEdge("Claire", "Jonny")

console.log(graph.nodes.connections)

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请只留下代码的相关部分。深度优先代码在哪里？这里的所有内容都是BFSOK，请尝试深度优先搜索版本，如果您有特定问题，您可以发布代码并询问。