public DecoyDuck()
 {
     flyBehaviour = new FlyNoWay();
     quackBehaviour = new MuteQuack();
 }
 public ModelDuck()
 {
     flyBehaviour = new FlyNoWay();
     quackBehaviour = new Quack();
 }
 public RubberDuck()
 {
     flyBehaviour = new FlyNoWay();
     quackBehaviour = new Squeak();
 }