public RedHeadDuck()
 {
     flyBehavior   = new FlyWithWings();
     quackBehavior = new Quack();
 }
 public ModelDuck()
 {
     flyBehavior   = new FlyNoWay();
     quackBehavior = new Quack();
 }
 public MallardDuck()
 {
     flyBehavior   = new FlyWithWings();
     quackBehavior = new Quack();
 }