LOOPS method Window.ItemMenu

[pamoroso]

Method ItemMenu of the LOOPS class Window creates and returns a standard menu record.

What methods or functions are supposed to be called to display such menus? Ordinary Interlisp menu functions such as MENU? If so, I'm confused as to why ItemMenu is a method instead of a function, as it does essentially the same thing as function NiceMenu which isn't tied to a class. I would have expected a related Window method to display a ItemMenu menu.