public void QualifiedCertification()
        {
            var course                   = new Course(5, "Microsoft SQL Server Database Development");
            var exam                     = new Exam(6, "70-433", "Microsoft SQL Server 2008, Database Development");
            var certification            = new Certification(5, "MCTS", "Microsoft Certified Technical Specialist in SQL Server 2008, Database Development");
            var certificationRequirement = new CertificationRequirement(certification, exam, course);

            _student.PassExam(exam);

            List <int> qualifyCertifications = _student.GetStudentCertificationIds(new List <CertificationRequirement>()
            {
                certificationRequirement
            });

            Assert.Equal(5, qualifyCertifications.Single());
        }