public void TestMethod1(int customerId)
        {
            var repository = new StubCustomerRepository();

            var discount = new Discount(repository);

            discount.CalculateCustomerDiscount(customerId);
        }
        public void TestMethod1(int customerId, Level level, int points)
        {
            var repository = new StubCustomerRepository(level, points);

            var discount = new Discount(repository);

            discount.CalculateCustomerDiscount(customerId);
        }
        public void TestMethod(int customerId)
        {
            var repository = new SICustomerRepository();

            repository.InstanceBehavior = PexChooseBehavedBehavior.Instance;

            var discount = new Discount(repository);

            discount.CalculateCustomerDiscount(customerId);
        }