public static void Demo()
        {
            CounterContainer c  = new CounterContainer();
            CounterIncreaser c1 = new CounterIncreaser(c);
            CounterIncreaser c2 = new CounterIncreaser(c);

            Thread t1 = new Thread(c1.IncreaseCounter);
            Thread t2 = new Thread(c2.IncreaseCounter);

            t1.Start();
            t2.Start();

            t1.Join();
            t2.Join();

            Console.WriteLine(c.Counter);
        }
 public CounterIncreaser(CounterContainer container)
 {
     _container = container;
 }