Case study Course registration at the local university is currently done by hand. Students fill out forms that contain their course selections and return the forms to the registrar. Clerks then enter the selections into a database and a process is executed to create student schedules. The registration process takes from one to two weeks to complete.The university decided to investigate the use of an online registration system. This system would be used by professors to indicate the courses they would teach, by students to select courses, and by the registrar to complete the registration process.At the beginning of each semester students may request a course catalogue containing a list of course offerings for the semester. Information about each course, such as professor, department, and prerequisites will be included to help students make informed decisions.The new on$-$line registration system will allow students to select four course offerings for the coming semester. In addition, each student will indicate two alternative choices in case a course offering becomes filled or canceled. No course offering will have more than ten students. No course offering will have fewer than three students. A course offering with fewer than three students will be canceled. Once the registration process is completed for a student, the registration system sends information to the billing system, so the student can be billed for the semester.Professors must be able to access the on$-$line system to indicate which courses they will be teaching. They will also need to see which students signed up for their course offering.For each semester, there is a period of time that students can change their schedules. Students must be able to access the on$-$line system during this time to add or drop courses. The billing system will credit all students for courses dropped during this period of time.By referring to above case study, draw the diagram below to represent the flow of the system.

$1.$UML use case diagram

$2.$Class diagram