public async Task <CourseDetailsViewModel> CourseDetails(int id)
        {
            // TODO: Add lecturer

            var course = await this.DbContext.Courses
                         .Include(c => c.Instances)
                         .FirstOrDefaultAsync(c => c.Id == id);

            ServiceModels.Lecturer.ViewModels.CourseDetailsViewModel model = this.Mapper.Map <CourseDetailsViewModel>(course);
            return(model);
        }
        public async Task <IActionResult> Details(int id)
        {
            //// TODO: Add lecturer

            //var course = this.contex.Courses
            //    .Include(c => c.Instances)
            //    .FirstOrDefault(c => c.Id == id);

            //var model = this.mapper.Map<CourseDetailsViewModel>(course);
            //// or afret adding services:
            ServiceModels.Lecturer.ViewModels.CourseDetailsViewModel courseModel = await this.coursesService.CourseDetails(id);

            return(View(courseModel));
        }