public void 第一集買了兩本_價格應為_200元()
        {
            // arrange
            var target = new PotterShopping();

            Dictionary<string, double> potterBooks = new Dictionary<string, double>();
            potterBooks.Add("episode1", 2);
            potterBooks.Add("episode2", 0);
            potterBooks.Add("episode3", 0);
            potterBooks.Add("episode4", 0);
            potterBooks.Add("episode5", 0);

            double expected = 200;

            // act
            double actual = target.PotterCalculator(potterBooks);

            // assert
            Assert.AreEqual(expected, actual);
        }
        public void 一二三四五集各買了一本_價格應為375元()
        {
            // arrange
            var target = new PotterShopping();

            Dictionary<string, double> potterBooks = new Dictionary<string, double>();
            potterBooks.Add("episode1", 1);
            potterBooks.Add("episode2", 1);
            potterBooks.Add("episode3", 1);
            potterBooks.Add("episode4", 1);
            potterBooks.Add("episode5", 1);

            double expected = 375;

            // act
            double actual = target.PotterCalculator(potterBooks);

            // assert
            Assert.AreEqual(expected, actual);
        }