Imagine a "DatabaseManager" class which job is, well, manage a database schema. If you need to create a mock of an "IDatabaseAdapterFactory" (and I use the term "mock" liberally) that returns a mock of an "IDatabaseAdapter" to test the manager, chances are big that you are testing implementation details. It's even worse if the subject-under-test also needs mocks of other dependencies. In this particular example, I'd prefer to actually include...