public void TestValidaCartaoTrue()
        {
            var service = new CartaoService();

            var result = service.ValidaCartao("4111111111111111");

            Assert.IsTrue(result is CartaoBase);
        }
        static void ValidaCartao(string numero)
        {
            try
            {
                var cartao = service.ValidaCartao(numero);

                Console.WriteLine($"{cartao.CardBrand} {cartao.CardNumber} {cartao.IsValid}");
            }
            catch (CartaoInvalidoExcepion ex)
            {
                Console.WriteLine($"{ex.Message}");
            }
        }
        public void TestValidaCartaoFalse()
        {
            var service = new CartaoService();

            try
            {
                service.ValidaCartao("12345");
                Assert.Fail("no exception thrown");
            }
            catch (System.Exception ex)
            {
                Assert.IsTrue(ex is CartaoInvalidoExcepion);
            }
        }