Application requests are data structures, not objects. Unit testing data structures is like testing getters and setters. There's no behavior to test, so there isn't much value in trying to unit test request objects and DTOs. These structures will be covered as a side effect of more elaborate tests, such as Integration or Acceptance tests.

Commands are an alternative to request objects. We could design a Service with multiple Application methods, and each one of them with the parameters you'd put inside the Request. This is OK for simple applications, but we'll worry about this topic later.