Homework!!!

Write three classes: Student, Course and School. Students should have name and unique number (inside the entire School). Name can not be empty and the unique number is between 10000 and 99999. Each course contains a set of students. Students in a course should be less than 30 and can join and leave courses.
Write following unit tests: 
1. Verify max number of students in group.
2. Check whether number entire School is unique.
3. Student Name cannot be empty.