@Test
public void test(){
deleteAndPopulateTables("students", "courses", "registrations");
Student student = Student.findById(1);
List<Course> courses = student.getAll(Course.class);
a(2).shouldBeEqual(courses.size());
student = Student.findById(2);
courses = student.getAll(Course.class);
a(1).shouldBeEqual(courses.size());
Course c = Course.findById(1);
List<Student> Students = c.getAll(Student.class);
a(2).shouldBeEqual(Students.size());