Draw a class diagram representing a book defined by the following statement: "A book is composed of a number of parts, which in turn are composed of a number of chapters. Chapters are composed of 4. sections." Focus only on classes and relationships. Extend the class diagram of Exercise 2-6 to include the following attributes a book includes a publisher, publication date, and an ISBN a part includes a title and a number a chapter includes a title, a number, and an abstract . a section includes a title and a number