public void Test_calculateServiceCharge_ColdFood()
        {
            string[] testBill = new string[] { "Cola", "Coffee", "Cheese Sandwich" };
            double   expected = 0.35;
            double   actual   = BillCalculator.calculateServiceCharge(testBill);

            Assert.AreEqual(expected, actual);
        }
        public void Test_calculateServiceCharge_Maximum()
        {
            List <string> testBill = new List <string>();

            //Create very large bill
            for (int a = 0; a < 40; a = a + 1)
            {
                testBill.Add("Steak Sandwich");
            }

            double expected = 20;
            double actual   = BillCalculator.calculateServiceCharge(testBill);

            Assert.AreEqual(expected, actual);
        }