public static void HelloTask()
        {
            Thread.Sleep(1000);
            Console.WriteLine("Hello");
        }

        public static void WorldTask()
        {
            Thread.Sleep(1000);
            Console.WriteLine("World");
        }
        public static void ContinuationTask()
        {
            Task task = Task.Run(() => HelloTask());
            //Starts executing this after completion of HelloTask.
            //if the antecedent task produces result, it can be supplied as input to continuation taks
            task.ContinueWith((prevTask) => WorldTask());
            //Overloads
            task.ContinueWith((prevTask) => WorldTask(), TaskContinuationOptions.OnlyOnRanToCompletion);
            task.ContinueWith((prevTask) => WorldTask(), TaskContinuationOptions.OnlyOnFaulted);

            Console.WriteLine("Finished Processing. Press a key to end");
            Console.ReadKey();
        }