public void Test_Customer_Buy_First_Episode_of_Potter_Book_The_Price_Should_be_100()
        {
            //Arrange
            double expect = 100;
            Customer customer = new Customer();
            Book book = GetSingleEpisode();
            customer.Buy(book);

            //Act
            Employee employee = new Employee();
            double actual = employee.GetPrice(customer.BuyingBook);

            //Assert
            Assert.AreEqual(expect, actual);
        }
        public void Test_Customer_Buy_First_and_Second_Third_Episode_of_Potter_Price_Should_be_270()
        {
            //Arrange
            double expect = 270;
            Customer customer = new Customer();
            List<Book> books = GetThreeDifferentEpisode();
            customer.Buy(books);

            //Act
            Employee employee = new Employee();
            double actual = employee.GetPrice(customer.BuyingBook);

            //Assert
            Assert.AreEqual(expect, actual);
        }