First, develop a three-layer architectural design of the book exchange system. In Chapter 7 you developed a use case diagram, a class diagram, and a system sequence diagram for the use cases add a seller and Record a book order. Based on those solutions or others provided by your teacher, develop a first-cut DCD by type casting the attributes and adding navigation visibility. Then for each use case develop a set of CRC cards. Add method names to the classes in the DCD based on the responsibilities identified on the CRC cards.