public HttpResponseMessage Update(HttpRequestMessage request, KhachHangViewModel khachhang)
        {
            return(CreateHttpResponse(request, () =>
            {
                HttpResponseMessage response = null;
                if (!ModelState.IsValid)
                {
                    response = request.CreateResponse(HttpStatusCode.BadRequest, ModelState);
                }
                else
                {
                    KhachHang NewKh = new KhachHang();
                    NewKh.UpdateKhachHang(khachhang);
                    _khachHangService.Edit(NewKh);
                    _khachHangService.SaveChange();
                    response = request.CreateResponse(HttpStatusCode.OK, khachhang);
                }

                return response;
            }));
        }