I think the reason something like this was not already in `Functions` is that it is not the usual idiom; it is the equivalent of using reflection in Java to find if a method is overridden, rather than using plain old object-oriented design. And anyway calling `Descriptor.getClass()` is a bad idea since it prevents there from being multiple `UserPropertyDescriptor`s with the same implementation class but different `id`s.

A simpler approach would be to extract the section of `User/configure.jelly` that you want to make optional into a `UserProperty/*.jelly`; `PaneStatusProperties` could then override this view to be empty.