Feature request: Add the ability to determine why a particular class is not initialized

I'm getting a warning in https://github.com/jpschewe/fll-sw/blob/4f157788eea59a514995db7e4654c9df674cdbc0/src/main/java/fll/scheduler/SchedulerUI.java#L278 that the method createMenubar is being called with a receiver @UnderInitialization(javax.swing.JFrame.class). However as near as I can tell all instance variables are initialized by this point, so I would expect the receiver to be @UnderInitialization(SchedulerUI.class).
If there was a way to put checker into a mode that would explain why this object isn't initialized yet, that would be very helpful. Perhaps something that lists the instance variables that are not know to be initialized when the method call is being made. That would help track down the problems.

Start with the warning at src/main/java/fll/scheduler/SchedulerUI.java line 278 and the createMenubar call described in the issue. Trace how the checker determines the receiver's initialization type, then identify where a diagnostic mode could explain the missing initialization facts. Done means the checker can report why a class is not considered initialized, including relevant uninitialized instance variables when applicable.