public void GetStudentByIdShouldReturnTheStudentWithTheId()
        {
            var student1 = new Student("Pesho");
            var student2 = new Student("Pesho");

            var school = new SchoolClass();
            int student1Id = school.RecordStudent(student1);
            int student2Id = school.RecordStudent(student2);

            Assert.AreSame(student1, school.GetStudentById(student1Id), "The first student is not the same as the returned student with the first id");
            Assert.AreSame(student2, school.GetStudentById(student2Id), "The second student is not the same as the returned student with the second id");
        }
        public void GetStudentByIdShouldReturnNullWhenStudentIdIsNotFound()
        {
            var school = new SchoolClass();
            var student = new Student("Pesho");

            var id = school.RecordStudent(student);
            var notExistingId = id + 1;

            Assert.IsNull(school.GetStudentById(notExistingId));
        }