// in Output window when debugging you can see the counter = 2 instances
 public HomeController(IValueCalculator calcParam, IValueCalculator calcParam2, IValueCalculatorDiscount calcDiscountParam) // constructor injection
 {
     calc         = calcParam;
     calcDiscount = calcDiscountParam;
 }
 public ShoppingCartDiscount(IValueCalculatorDiscount calcParam)
 {
     calc = calcParam;
 }