(NEW) Illustrative classes:
- App: simulates a production application
- BusinessOperation<T>: abstraction over any operation that can
potentially fail
- FindCustomer <: BusinessOperation<String>: illustrative
operation that can throw an error
- Retry <: BusinessOperation<T>: transparently implements the
retry mechanism
- Several "business" exceptions:
- BusinessException: top-level
- CustomerNotFoundException: can be ignored
- DatabaseNotAvailableException: fatal error
(NEW) .puml and .png for UML