This should be a mock-up of the classes and methods you will need to make this application work. Think console applications as we did in AP. You don't want these classes to be tied to GWT in anyway. It won't be complete and could be wrong in some areas but the team needs to have an idea of where things are going to allow the work to be separated into meaningful chunks. The question here is if I was to make this a console application how would I design my classes to accomplish the application. All method in these classes must be exhaustively unit-tested. An object diagram