(a) Could format be changed during a Counter object's lifetime?
|These questions are for you to answer|
Could Counter class be changed in any way other than adding new abstract methods?
|You can also change the specification of existing methods. If this is the case, you will also have to submit the specification of all modified methods as well|
Based on my analysis I arrived at the conclusion that (for example) redo should NOT be a method of Counter, but instead a static method in some other class. Is this OK?
|Yes. You should plan the specifcation of an undo/redo service. This service can be realized as either a method, a static method, or some other thing, whatever you feel is better|
(a) Can we assume that the tree of Counters is not changed during all undo/redo
|(a) No, you cannot assume that (b) In this homework you should define the semantics|