public HomeworkModel GetHomeworkById(int id,
                                             [ValueProvider(typeof(HeaderValueProviderFactory <string>))] string accessToken)
        {
            return(this.PerformOperationAndHandleExceptions(() =>
            {
                var dbContext = new TimetableContext();
                var user = this.GetUserByAccessToken(accessToken, dbContext);
                var homework = user.Homeworks.FirstOrDefault(l => l.Id == id);

                var models = HomeworkModel.Parse(homework);

                return models;
            }));
        }