public ActionResult Edit(int?id)
        {
            if (id == null)
            {
                return(new HttpStatusCodeResult(HttpStatusCode.BadRequest));
            }
            ContactGroup contactGroup = _contactGroupService.FindById((int)id);

            if (contactGroup == null)
            {
                return(HttpNotFound());
            }
            return(PartialView("_Edit", contactGroup.MapModelToViewModel()));
        }