QUESTION
 Understanding inheritance of visual parts in VisualAge.

ANSWER
 When inheriting visual parts, you don't have the same flexibility
 as when inheriting scripts. In the case where you override the
 inherited visual part ("or specialize it"), any subsequent changes
 to the superclass part are not visible to the subclass,
 as saving the changes causes the regeneration of the
 abtBuildInternals and other runtime methods, which are
 completely overridden by the same runtime methods in the subclass.

 Scenarios for VISUAL PARTS in VisualAge:
  *Class B is inherited from class A.  Class B remains unchanged.  Class
    A is changed.  The changes to class A will show up in class B.

  *Class B is inherited from class A.  Class B is changed or specialized.
    Class A is then changed.  The changes to class A will now NOT show up in
    class B.

 As a result, inheriting visual parts should be thought of as a
 one-time copy.  Therefore, you should be careful to stabilize
 the visual part class you are inheriting from as much
 as possible before inheriting.