public async Task TestAboutDialog()
{
var app = AvaloniaApp.GetApp();
var window = AvaloniaApp.GetMainWindow();
await FocusFilePanelStep.FocusFilePanelAsync(window);
OpenAboutDialogStep.OpenAboutDialog(window);
await DialogOpenedCondition.CheckIfDialogIsOpenedAsync <AboutDialog>(app);
_dialog = app
.Windows
.OfType <AboutDialog>()
.Single();
var githubButton = _dialog.GetVisualDescendants().OfType <Button>().SingleOrDefault();
Assert.NotNull(githubButton);
Assert.True(githubButton.IsDefault);
Assert.True(githubButton.IsEnabled);
}