public List <ThemeModel> GetAllThemes(string levelTag, int subjectId)
        {
            var subject = GetSubject(levelTag, subjectId);

            var subjectPage = new SubjectPage(Driver, subject.Url);
            var themeList   = subjectPage.GetAllThemes().Select(o => new ThemeModel {
                ThemeId = o.ThemeId, Name = o.Name, Url = o.Url
            }).ToList();

            return(themeList);
        }
        public SubjectModel GetSubject(string levelTag, int subjectId)
        {
            var subjectList = GetAllSubjects(levelTag);

            var subject     = subjectList.FirstOrDefault(o => o.SubjectId == subjectId);
            var subjectPage = new SubjectPage(Driver, subject.Url);

            subject.Themes = subjectPage.GetAllThemes().Select(o => new ThemeModel {
                ThemeId = o.ThemeId, Name = o.Name, Url = o.Url
            }).ToList();
            subject.Categories = subjectPage.GetAllCategories().Select(o => new CategoryModel {
                Id = o.Id, Name = o.Name
            }).ToList();

            return(subject);
        }