[TestMethod]
    public void TestThatSomethingInsideMyApplicationWorks()
    {
        using (var applicationInstance = new ApplicationInstance())
        {
            applicationInstance.Launch("MyApp.exe");

            applicationInstance.Run(async () =>
                {
                    // This code runs on the UI thread of the application
                    // yes, async is available
                    await Task.Delay(5000);

                    // Using methods defined in the target application
                    await IoC.Get<IEventAggregator>().Publish(new OpenWindowEvent());


                    // Or using UI code
                    var myWindow = Application.Current.MainWindow;
                    myWindow.TextBox1.Text = "Bob";
                });
        }
    }