private async Task HandleChapterAchievement(int userId, List <Achievement> achievementsForUser, Chapter chapter)
        {
            List <Chapter> chaptersForUser = await courseRepo.GetCompletedChaptersForUser(userId);

            if (!chaptersForUser.Contains(chapter))
            {
                await InsertUserChapter(userId, chapter.ChapterId);

                Achievement achievementForChapterCount = await achievementService.GetAchievementForChapterCount(chaptersForUser.Count + 1);

                if (achievementForChapterCount != null && !achievementsForUser.Contains(achievementForChapterCount))
                {
                    await achievementService.InsertUserAchievement(userId, achievementForChapterCount.AchievementId);
                }
            }
        }