public void Execute()
        {
            var selfCheckout = new SelfCheckout();

            foreach (var index in Enumerable.Range(1, 3))
            {
                selfCheckout = EnterItem(selfCheckout, index);
            }

            var formattedSelfCheckout = new FormattedSelfCheckout(selfCheckout);

            Console.WriteLine("Subtotal: {0}", formattedSelfCheckout.SubTotal());
            Console.WriteLine("Tax: {0}", formattedSelfCheckout.Tax());
            Console.WriteLine("Total: {0}", formattedSelfCheckout.Total());
        }
        public void Execute()
        {
            var selfCheckout = new SelfCheckout();

            foreach (var index in Enumerable.Range(1, 3))
            {
                selfCheckout = EnterItem(selfCheckout, index);
            }

            var formattedSelfCheckout = new FormattedSelfCheckout(selfCheckout);

            Console.WriteLine("Subtotal: {0}", formattedSelfCheckout.SubTotal());
            Console.WriteLine("Tax: {0}", formattedSelfCheckout.Tax());
            Console.WriteLine("Total: {0}", formattedSelfCheckout.Total());
        }