public async Task GetAvailableSubjects_gets_available_subjects_by_teacher_id_is_equal()
        {
            var            service = new TeacherActivity(context);
            List <Subject> result  = await service.GetAvailableSubjects(1);

            Assert.AreEqual("Algorithm Theory", result[0].Title);
        }
        public async Task GetAvailableSubjects_gets_available_subjects_by_teacher_id_is_not_null()
        {
            var            service = new TeacherActivity(context);
            List <Subject> result  = await service.GetAvailableSubjects(1);

            Assert.IsNotNull(result);
        }