Using Task and Async in Controllers

 public async Task<ActionResult> AddPhoneNumber(AddPhoneNumberViewModel model)        {            if (!ModelState.IsValid)            {                return View(model);            }            // Generate the token and send it            var code = await UserManager.GenerateChangePhoneNumberTokenAsync(User.Identity.GetUserId(), model.Number);            if (UserManager.SmsService != null)            {                var message = new IdentityMessage                {                    Destination = model.Number,                    Body = "Your security code is: " + code                };                await UserManager.SmsService.SendAsync(message);            }            return RedirectToAction("VerifyPhoneNumber", new { PhoneNumber = model.Number });        }