public IActionResult CreatePizza(CreatePizzaCommand command)
        {
            var newPizza = new Pizza {
                Size = command.Size
            };

            newPizza.Id = _pizzas.Select(p => p.Id).Max() + 1;

            _pizzas.Add(newPizza);

            return(Created($"api/pizzas/{newPizza.Id}", newPizza));
        }
        public IActionResult CreatePizza(CreatePizzaCommand command)
        {
            var newPizza = new Pizza {
                Size = command.Size
            };

            //to set the id to the next id after the greatest id currently on a pizza:
            //take the pizzas collection > transform it into a collection of just ids > and then use .Max() to give me the biggest id and then add 1 to create the id of the new pizza.
            newPizza.Id = _pizzas.Select(p => p.Id).Max() + 1;
            _pizzas.Add(newPizza);

            return(Created($"api/pizzas/{newPizza.Id}", newPizza));
        }