public void UpdateProblemClass(DataTransfer.ProblemClass dto)
        {
            roleVerifier.AuthenticateForAllRoles(OKBRoles.OKBAdministrator);

            using (OKBDataContext okb = new OKBDataContext()) {
                DataAccess.ProblemClass entity = okb.ProblemClasses.FirstOrDefault(x => x.Id == dto.Id);
                Convert.ToEntity(dto, entity);
                okb.SubmitChanges();
            }
        }
        public long AddProblemClass(DataTransfer.ProblemClass dto)
        {
            roleVerifier.AuthenticateForAllRoles(OKBRoles.OKBAdministrator);

            using (OKBDataContext okb = new OKBDataContext()) {
                DataAccess.ProblemClass entity = Convert.ToEntity(dto); entity.Id = 0;
                okb.ProblemClasses.InsertOnSubmit(entity);
                okb.SubmitChanges();
                return(entity.Id);
            }
        }