public void Should_only_charge_for_first_hour()
        {
            var oneHourPriceRule = new OneHourPriceRule();
            decimal amount = oneHourPriceRule.Amount(new TimeSpan(1, 30, 0));

            Assert.AreEqual(10m, amount);
        }
        public void Should_return_correct_amount_for_only_minutes()
        {
            var oneHourPriceRule = new OneHourPriceRule();
            decimal amount = oneHourPriceRule.Amount(new TimeSpan(0, 30, 0));

            Assert.AreEqual(5m, amount);
        }