Leetcode 133 - Clone Graph - revise the code to fit into online judge

Leetcode133CloneGraph2.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace cloneGraph
{
    /*
     * source code from web blog: 
     * http://www.programcreek.com/2012/12/leetcode-clone-graph-java/
     * 
     * Leetcode Clone Graph  
     * 
     * http://www.cnblogs.com/springfor/p/3874591.html
     * 
     */
    /**
        Definition for undirected graph.
    */
    // Undirected Graph Node - Node
    class UndirectedGraphNode   
    {
        public int label;
        public List<UndirectedGraphNode> neighbors;

        public UndirectedGraphNode(int x)
        {
            label = x;
            neighbors = new List<UndirectedGraphNode>();
        }
    }

    class Program
    {   
        static void Main(string[] args)
        {
            // {0, 1, 2#1, 2#2, 2}

            UndirectedGraphNode node0 = new UndirectedGraphNode(0);
            UndirectedGraphNode node1 = new UndirectedGraphNode(1);
            UndirectedGraphNode node2 = new UndirectedGraphNode(2);

            List<UndirectedGraphNode> list0 = new List<UndirectedGraphNode>();
            list0.Add(node1);
            list0.Add(node2);
            node0.neighbors = list0;

            node1.neighbors = new List<UndirectedGraphNode>();
            node1.neighbors.Add(node2);

            node2.neighbors = new List<UndirectedGraphNode>();
            node2.neighbors.Add(node2);

            UndirectedGraphNode newClone = cloneGraph(node0);
            UndirectedGraphNode newClone2 = cloneGraph(node1);
            UndirectedGraphNode newClone3 = cloneGraph(node2); 
        }       
        
        /*
         * Quickly go over the code with test case
         * 
         */
        public static UndirectedGraphNode cloneGraph(UndirectedGraphNode node) {
            if(node == null)
                return null;
 
            Queue<UndirectedGraphNode> queue = new Queue<UndirectedGraphNode>();
            Dictionary<UndirectedGraphNode, UndirectedGraphNode> map = 
                                   new Dictionary<UndirectedGraphNode,UndirectedGraphNode>();
 
            UndirectedGraphNode newHead = new UndirectedGraphNode(node.label);
 
            queue.Enqueue(node);
            map.Add(node, newHead);
 
            while(queue.Count > 0 ){
                UndirectedGraphNode curr = (UndirectedGraphNode)queue.Dequeue();                

                IList<UndirectedGraphNode> currNeighbors = curr.neighbors; 
 
                foreach (UndirectedGraphNode aNeighbor in currNeighbors){
                    if(!map.ContainsKey(aNeighbor)){
                        UndirectedGraphNode copy = new UndirectedGraphNode(aNeighbor.label);

                        map.Add(aNeighbor,copy);

                        map[curr].neighbors.Add(copy);

                        queue.Enqueue(aNeighbor);
                    }else{
                        map[curr].neighbors.Add(map[aNeighbor]);
                    }
                } 
            }

            return newHead;
        }
    }    
}