public IHttpActionResult GetCoursesNeedToRepeat(string userLogin)
        {
            try
            {
                List <CourseDTO> coursesNeedToRepeat = new List <CourseDTO>();

                List <CourseSubscriptionDTO> courseSubscriptionDTOs = new List <CourseSubscriptionDTO>();

                courseSubscriptionDTOs = userSubscriptions.GetCourseSubscriptions(userLogin).ToList();

                courseSubscriptionDTOs.ForEach(courseSub =>
                {
                    if (quiz.GetCardsForRepeat(statistics.GetCourseStatistics(userLogin, courseSub.CourseId)).Count() > 0)
                    {
                        coursesNeedToRepeat.Add(catalogBll.GetCourseDTO(courseSub.CourseId));
                    }
                });

                return(Ok(coursesNeedToRepeat));
            }
            catch (Exception ex)
            {
                return(BadRequest(ex.Message));
            }
        }