public MainWindow()
        {
            InitializeComponent();

            Title = "Animate Property using a Storyboard";

            Panel panel;

            Button button;

            Content =
                panel = new StackPanel()
                    .AddChildren(
                        button = new Button() { Content = "Button" });

            var storyboard =
                new Storyboard()
                    .AddChildren(
                        new DoubleAnimation()
                        {
                            From = 200,
                            To = 300,
                            Duration = new Duration(TimeSpan.FromMilliseconds(1000))
                        }
                            .SetTargetObject(this, button, Button.WidthProperty));

            panel.AddChildren(
                new Button() { Content = "Start" }
                    .AddClick((s, args) => storyboard.Begin(this)));
        }