private void CascadeDeleteCategories(DatabaseModelType contest)
        {
            foreach (var children in contest.Children.ToList())
            {
                this.CascadeDeleteCategories(children);
            }

            this.Data.ContestCategories.Delete(contest);
            this.Data.SaveChanges();
        }
        private void CascadeDeleteCategories(DatabaseModelType contest)
        {
            foreach (var children in contest.Children.ToList())
            {
                this.CascadeDeleteCategories(children);
            }

            this.Data.ContestCategories.Delete(contest);
            this.Data.SaveChanges();
        }