if you are creating a new project and the App/Window are the new Desktop controls, then the library will show Desktop controls
you are missing that the identification may say PopupArrow but the Super is in fact DesktopPopupArrow and you need to search the documentation for DesktopPopupArrow instead
The Deprecated controls will appear in the library when you are working with a deprecated Window class. So instead of a super of DesktopWindow, just Window
That said, I don’t suggest doing this. The new views and old classes (and vice versa) don’t always work well together.