public void TestByCommandExtensions()
{
var buttons = ((AppVar)_ctrl).LogicalTree().ByType<Button>();
AppVar button2 = buttons.ByCommand(ApplicationCommands.Close).Single();
Assert.AreEqual(button2, _ctrl._button2);
button2 = buttons.ByCommand(typeof(ApplicationCommands).FullName, "Close").Single();
Assert.AreEqual(button2, _ctrl._button2);
}