feat: add DelayQueueDemo showcasing delayed task execution with DelayQueue

Implemented DelayQueueDemo.java to demonstrate scheduling tasks using DelayQueue,
a thread-safe unbounded blocking queue. Illustrates how elements become available
only after their delay expires via DelayedTask implementation using getDelay() and
compareTo() for time-based ordering.

Signed-off-by: https://github.com/Someshdiwan <[email protected]>

Author: Someshdiwan

Section 25 Collections Frameworks/Queue Interface/Delay Queue/src/DelayQueueDemo.java

@@ -9,6 +9,7 @@ public static void main(String[] args) throws InterruptedException {
         // Elements can only be taken from the queue when their delay has expired
         // Useful for scheduling tasks to be executed after a certain delay
         // internally priority queue
+
         BlockingQueue<DelayedTask> delayQueue = new DelayQueue<>();
         delayQueue.put(new DelayedTask("Task1", 5, TimeUnit.SECONDS));
         delayQueue.put(new DelayedTask("Task2", 3, TimeUnit.SECONDS));
@@ -22,7 +23,6 @@ public static void main(String[] args) throws InterruptedException {
 }
 
 class DelayedTask implements Delayed {
-
     private final String taskName;
     private final long startTime;
 
@@ -51,4 +51,4 @@ public int compareTo(Delayed o) {
     public String getTaskName() {
         return taskName;
     }
-}
+}