public IActionResult Edit(Tenant model) { if (ModelState.IsValid) { if (model.Email != _tenants.Get(model.Id).Email&& _tenants.IsEmailTaken(model.Email)) { ModelState.AddModelError("Tenant.Email", "This email is already taken."); return(View(model)); } _tenants.Update(model); return(RedirectToAction("Index", new { id = model.Id })); } return(View(model)); }