public CategoryView ToView()
        {
            var categoryView = new CategoryView
            {
                Id              = Id,
                Name            = Name,
                ParentId        = ParentId,
                Description     = Tools.Render(Description, FileData),
                CategoriesCount = Categories.Count(),
                Categories      = Categories.Select(c => c.ToLink()).ToArray(),
                ProblemsCount   = Problems.Count(),
                ExercisesCount  = Exercises.Count(),
                QuizCount       = Quiz.Count()
            };

            return(categoryView);
        }