DelayQueue clear() method in Java

// Java program to illustrate the clear() method
// of DelayQueue class

import java.util.concurrent.DelayQueue;
import java.util.concurrent.Delayed;
import java.util.concurrent.TimeUnit;

public class GFG {
    public static void main(String args[])
    {
        // Create a DelayQueue instance
        DelayQueue<Delayed> queue = new DelayQueue<Delayed>();

        // Create an Object of type Delayed
        Delayed obj = new Delayed() {
            public long getDelay(TimeUnit unit)
            {
                return 24; // some value is returned
            }

            public int compareTo(Delayed o)
            {
                if (o.getDelay(TimeUnit.DAYS) > 
                                  this.getDelay(TimeUnit.DAYS))
                    return 1;
                else if (o.getDelay(TimeUnit.DAYS) == 
                                  this.getDelay(TimeUnit.DAYS))
                    return 0;
                return -1;
            }
        };

        // Add the obj to the queue
        queue.add(obj);

        // Check if queue is empty
        System.out.println("Is queue empty() : "
                           + queue.isEmpty());

        // Remove all elements from queue
        // using clear() method
        queue.clear();

        // Check if queue is empty
        System.out.println("Is queue empty after calling clear() : "
                           + queue.isEmpty());
    }
}