private void DisplayProducts(IVendingMachineService vendingMachineService)
{
foreach (var vendingMachineItem in vendingMachineService.GetProductMap())
{
Console.WriteLine(vendingMachineItem.Value.TotalItem > 0
? $"{vendingMachineItem.Key} {vendingMachineItem.Value.ProductName} ({vendingMachineItem.Value.TotalItem}): ${vendingMachineItem.Value.Price}"
: $"{vendingMachineItem.Key} {vendingMachineItem.Value.ProductName} ({vendingMachineItem.Value.TotalItem}): ${vendingMachineItem.Value.Price}: is out of stock.");
}
}
