public IActionResult Create(Topping topping)
 {
     if (ModelState.IsValid)
     {
         _toppingRepository.AddTopping(topping);
         return(RedirectToAction(nameof(Index)));
     }
     ViewBag.Categories = _categoryRepository.ToppingCategories;
     ViewBag.Units      = _toppingRepository.Units;
     return(View(topping));
 }