private static async void Consumer(AsyncProducerConsumerCollection <int> queue)
        {
            while (true)
            {
                int val = await queue.Take();

                Console.WriteLine("Procesing");
                Thread.Sleep(val);
                Console.WriteLine("Done");
            }
        }
        static void Main(string[] args)
        {
            AsyncProducerConsumerCollection <int> queue = new AsyncProducerConsumerCollection <int>();

            // How many consumers to create
            for (int nConsumer = 0; nConsumer < 2; nConsumer++)
            {
                Consumer(queue);
            }


            Console.WriteLine("Press enter to add work items to queue");
            Random rnd = new Random();

            while (true)
            {
                Console.ReadLine();
                queue.Add(3000);
                Console.WriteLine("Added..");
            }
        }