public int SetCourseOpen(CourseOpen courseOpen)
        {
            var id = 0;

            if (_allCoursesOpen.Where(d => d.CourseId == courseOpen.CourseId).Count() == 0)
            {
                id = _allCoursesOpen.OrderByDescending(d => d.Id).Select(d => d.Id).FirstOrDefault() + 1;
                _allCoursesOpen.Add(
                    new CourseOpen()
                {
                    Id           = id,
                    CourseId     = courseOpen.CourseId,
                    Attendees    = courseOpen.Attendees,
                    MaxAttendees = courseOpen.MaxAttendees
                }
                    );
                return(id);
            }

            _allCoursesOpen = _allCoursesOpen.Select(d =>
            {
                if (d.CourseId == courseOpen.CourseId)
                {
                    id             = courseOpen.Id;
                    d.Attendees    = courseOpen.Attendees;
                    d.MaxAttendees = courseOpen.MaxAttendees;
                    return(d);
                }

                return(d);
            }).ToList();

            return(id);
        }
        public IActionResult Post([FromBody] CourseOpen openCourse)
        {
            if (ModelState.IsValid)
            {
                int id = _courseOpenRepo.SetCourseOpen(openCourse);
                if (id > 0)
                {
                    openCourse.Id = id;
                    return(new CreatedResult("/courseopen/post", openCourse));
                }
                else
                {
                    return(new NotFoundResult());
                }
            }

            return(BadRequest("Invalid Course Open Model"));
        }