University Library System This case is a simplified (initial draft) of a new system for the University Library. Of course, the library system must keep track of books. Information is maintained about both book titles and the individual book copies. Book titles maintain information about title, author, publisher, and catalog number. Individual copies maintain copy number, edition, publication year, ISBN, book status (whether it is on the shelf or loaned out), and date due back in. The library also keeps track of patrons to the library. Since it is a university library, there are several types of patrons, each with different privileges. There are faculty patrons, graduate student patrons, and undergraduate student patrons. Basic information about all patrons is name, address, and telephone number. For faculty patrons, additional information is office address and telephone number. For graduate students, information such as graduate program and advisor information is maintained. For undergraduate students program and total credit hours are maintained. The library also keeps information about library loans. A library loan is a somewhat abstract object. A loan occurs when a patron approaches the circulation desk with a stack of books to check out. Over time a patron can have many loans. A loan can have many physical books associated with it. (And a physical book can be on many loans over a period of time. Information about past loans is kept in the database.) So, in this case, it is recommended that an association class be created for loaned books. If a book is checked out that a patron wants, he/she can put that title on reserve. This is another class that does not represent a concrete object. Each reservation is for only one title and one patron. Information such as date reserved, priority, and date fulfilled is maintained. When it is fulfilled, the system associates it with the loan on which it was checked out.

my question is follow that

1. Write the use case description for checking out books with one any exceptional case.