// GET: Course/Details/5
        public ActionResult Details(int id)
        {
            Course course = courseService.Get(id);
            IEnumerable <Prerequisite> prerequisites   = prerequisiteService.GetAll().ToList();
            CourseViewModel            courseViewModel = new CourseViewModel
            {
                Course        = course,
                Prerequisites = prerequisites.Where(x => x.CourseId == course.Id).Select(x => x.CoursePrerequisite).ToList()
            };

            return(View(courseViewModel));
        }