Rõ ràng từ sơ đồ trong hình. (bên trái), đối tượng được phân bổ trong borrowDocument (Loan1) được chứa bên trong danh sách các khoản cho vay được sở hữu bởi Libraryl đối tượng, đại diện cho toàn bộ thư viện. Loan1 tài liệu tham khảo các tài liệu và người sử dụng tham gia vay. | Object Diagram 9 As apparent from the diagram in Fig. left the object allocated inside borrowDocument Loanl is contained inside the list of loans possessed by the object Libraryl which represents the whole library. Loanl references the document and the user participating in the loan. These are objects of type Book Journal TechnicalReport and User Internaluser respectively as depicted in the static object diagram. In turn they have a reference to the loan object bidirectional link in Fig. . On the contrary the objects Loan2 and Loan3 are not accessible from the list of loans held by Library1. They are temporary objects created to manage the deletion of a loan method returnDocument line 70 and to check the existence of a loan between a given user and a given document method isHolding line 78 . However none of them is in turn referenced by the associated user document unidirectional link in Fig. . The dynamic object diagram on the right of Fig. was obtained by executing the eLib program under the following scenario Time Operation 1 2 3 4 5 6 An internal user is registered into the library. Another internal user is registered. A book is archived into the library Another book is archived. A journal is archived into the library. The journal archived at time 5 is borrowed by the first registered user. 7 The journal borrowed at time 6 is returned to the library and the loan is closed. 8 The librarian verifies that the loan was actually closed. The time intervals indicating the life span of the inter-object relationships are in square brackets. The objects InternalUser1 InternalUser2 represent the two users created at times 1 and 2 while Book1 Book2 Journal1 are the objects created when two books and a journal are archived into the library at times 3 4 5 respectively. When a loan is opened between InternalUser1 and Journal1 at time 6 the object Loan1 is created referencing and referenced by the user and document involved in the loan. At time 7 the loan .
