question: public void updateCurrentState ( String whatHappened ) { UndoEvent undoEvent = createUndoEventForCurrentState ( whatHappened ) ; if ( undoEvent != null && undoStack != null ) { undoStack . setTheWayThingsAre ( undoEvent ) ; } }
target:  Called by anything that knows that the EOMG has arrived at a stable state that should be kept for Undo actions.