public IActionResult Update(Guid id)
        {
            var vm = new PartialViewsUpdateViewModel
            {
                FirstName = new Partial1UpdateViewModel {
                    Id = id
                },
                LastName = new Partial2UpdateViewModel {
                    Id = id
                }
            };

            return(View(vm));
        }
        public IActionResult UpdateLastName(Guid id, PartialViewsUpdateViewModel vm)
        {
            if (id != vm.LastName.Id)
            {
                return(BadRequest());
            }

            ModelState.Clear();
            this.ValidateModel(vm.LastName, "LastName.");

            if (!ModelState.IsValid)
            {
                return(View("Update", vm));
            }

            return(RedirectToAction("Index"));
        }