5. What will happen if we do not ?
We may get an Exception which is unrelated
We may get an incorrect result
We may create an object which will fail at a totally
different and unrelated time
6. What should be checked ?
Constructors
Public, protected, package methods
7. When not to check ?
If the check is very expensive
a method which expects a sorted list
If the check will be done implicitly in the
computation
sorting automatically checks for comparable
instances
Possible to omit checks in private methods
