no edit summary
Actually Library.java is a class, I'm going to use it as an example
instead of student.java.
6. Renaming Java elements
I changed Video.java to Audio.java by changing the interface name.
click yes. Then the program will stop at La.addMedia(a).
I can choose run->step into in the menu to follow the program.
15.Using the Java browsing perspective
16.Writing and running JUnit tests