public List<Lead> GetBySpecification(LeadSpecification specification)
        {
            IQueryable<Lead> cases = _db.Leads;

            //if (specification.Id > 0)
            //{
            //    dbLetters = dbLetters.Where(c => c.Id == specification.Id);
            //}

            return cases.OrderBy(c => c.Id).Take(specification.Take).Skip(specification.Skip).ToList();
        }
        public List <Lead> GetBySpecification(LeadSpecification specification)
        {
            IQueryable <Lead> cases = _db.Leads;

            //if (specification.Id > 0)
            //{
            //    dbLetters = dbLetters.Where(c => c.Id == specification.Id);
            //}

            return(cases.OrderBy(c => c.Id).Take(specification.Take).Skip(specification.Skip).ToList());
        }