There are some instance (e.g. find and connect to a ClickOnce WPF application) where it's desirable or necessary to launch the WPF application outside of Test Studio's normal launch process, then, using an API call, instruct the framework to connect to and automate (i.e. run the rest of the test) the already running WPF process. This would be most useful for ClickOnce applications because the install path frequently changes. Using code it can find and launch the WPF application. If there was an API call provided, the coded step could tell Test Studio to connect to it and run the test normally from that point on.