content: package StacksAndQueues.Queue;
  
  public class QueueTest {
    public static void main(String[] args) {
  
      Queue<Integer> queue = new Queue<>();
      System.out.println("Queue created.");
  
      // should be 0
      System.out.println("\nSize of the queue: " + queue.size());
  
      System.out.println("\nEnqueueing items...");
      queue.enqueue(10);
      queue.enqueue(20);
      queue.enqueue(30);
      queue.enqueue(40);
      queue.enqueue(50);
      queue.enqueue(60);
      queue.enqueue(70);
      queue.enqueue(80);
  
      // should be 10, 20, 30, 40, 50, 60, 70, 80
      System.out.println("\nQueue items: " + queue.toString());
  
      // should be 8
      System.out.println("\nSize of the queue: " + queue.size());
  
      System.out.println("\nDequeueing items...");
      System.out.println(queue.dequeue()); // should be 10
      System.out.println(queue.dequeue()); // should be 20
      System.out.println(queue.dequeue()); // should be 30
  
      // should be 5
      System.out.println("\nSize of the queue: " + queue.size());
  
      System.out.println("\nDequeueing some more items...");
      System.out.println(queue.dequeue()); // should be 40
      System.out.println(queue.dequeue()); // should be 50
      System.out.println(queue.dequeue()); // should be 60
      System.out.println(queue.dequeue()); // should be 70
      System.out.println(queue.dequeue()); // should be 80
  
      // should be true
      System.out.println("\nIs the queue empty? " + queue.isEmpty());
    }
  }
  