Two queues implement a stack

import java.util.LinkedList;import java.util.Queue;//Two queues implement a stack, imagine the following is a stackpublic class StackByQuene {Queue queue1=new LinkedList<>();Queue queue2=new LinkedList<>();public void push(int node) //The first push to queue2, the next push to a non-empty queue,{if(!queue1.isEmpty())queue1.offer(node);elsequeue2.offer(node);}public Integer pop() //Which is not empty, which is popped into the other, leaving the last node, which is popping{if(!queue1.isEmpty()&&queue2.isEmpty()){while(queue1.size()>1){queue2.offer( queue1.poll());}return queue1.poll();}if(queue1.isEmpty()&&!queue2.isEmpty()){while(queue2.size()>1){queue1.offer(queue2.poll());}return queue2.poll();}return null;}@Overridepublic String toString() {return "StackQuene{" +"queue1=" + queue1 +", queue2=" + queue2 +'}';}public static void main(String[] args) {StackByQuene s=new StackByQuene();s.push(1);s.push(2);s.push(3);System.out.println(s);s.pop();System.out.println(s);s.push(4);s.push(5);System.out.println(s);s.pop();System.out.println(s);}}