Question

In the client-server contract model of method calling modifying the pre- and post-conditions in an overridden subclass method can be tricky. What is, and is NOT, allowed in junit or java?

Answer 1

Weaken preconditions are generally facilitated by subclasses in an inheritace hierarchy. Whereas the postconditions are powerful along with the invariants.Behaviourlal subtyping is always has its rules approximated. The class relationships exist between the supplier and the client classes. The supplier is pretended to provide a return state and the specific data which has less or no chances of violating the requirments of the client.The class invariants generally have a guarantee that the class's state will be maintained to fit the tolerances at the end of each extraction.