public MainWindow()
        {
            InitializeComponent();
            Animals = new ObservableCollection <Animal>();

            Frog frog  = new PolymorphismIntro.Frog(1, "Dart", true, 20);
            Dog  dog   = new PolymorphismIntro.Dog("Labradoodle", 35, "Pax", 51);
            Duck duck  = new PolymorphismIntro.Duck(12, "Kevin", 7);
            Frog frog2 = new PolymorphismIntro.Frog(5, "Crazzy", false, 2);
            Dog  dog2  = new PolymorphismIntro.Dog("Labradoodle", 7, "Sophie", 5);
            Duck duck2 = new PolymorphismIntro.Duck(39, "Obamuck", 500);


            Animals.Add(frog);
            Animals.Add(dog);
            Animals.Add(duck);
            Animals.Add(frog2);
            Animals.Add(dog2);
            Animals.Add(duck2);

            lvAnimals.ItemsSource = Animals;
        }
        public MainWindow()
        {
            InitializeComponent();
            Animals = new List <Animal>();
            Frog frog     = new PolymorphismIntro.Frog(4, "Kermit", false, 25);
            Dog  dog      = new PolymorphismIntro.Dog("Muppet", 20, "Rolf", 70);
            Duck duck     = new Duck(9, "Donald", 35);
            Dog  Clifford = new PolymorphismIntro.Dog("terrier", 200, "Clifford", 1000);
            Duck Daffy    = new Duck(5, "Daffy", 60);
            Frog Jerimiah = new Frog(3, "Jerimiah", true, 15);

            Animals.Add(frog);
            Animals.Add(dog);
            Animals.Add(duck);
            Animals.Add(Clifford);
            Animals.Add(Daffy);
            Animals.Add(Jerimiah);
            lvAnimals.ItemsSource = Animals;

            foreach (Animal a in Animals)
            {
                a.SayName();
            }
        }