private static void DoWork() { Duck mallard = new MallardDuck(); mallard.Display(); mallard.PerformQuack(); mallard.PerformFly(); Duck model = new ModelDuck(); model.Display(); model.PerformFly(); model.SetFlyBehaviour(new FlyRocketPowered()); model.PerformFly(); IQuackBehavior duckCaller = new DuckCaller(); duckCaller.Quack(); }