public void DeserializeExpandable()
        {
            // Arrange
            var json = File.ReadAllText("JSON/expandable.json");

            // Act
            var obj = StripeClient.Deserialize <Customer>(json);


            obj.Should().NotBeNull();
            obj.DefaultCard.Should().NotBeNull();
            obj.DefaultCard.AddressLine1.Should().Be("test", obj.DefaultCard.AddressLine1);
            obj.DefaultCard.CustomerId.Should().Be("cus_9iMkevoQCYMIzC", obj.DefaultCard.CustomerId);
        }
        public void DeserializeErrorTest()
        {
            // Arrange
            var json = File.ReadAllText("JSON/error.json");

            // Act
            var obj = StripeClient.Deserialize <StripeErrorEnvelope>(json);

            // Assert
            obj.Should().BeAssignableTo <StripeErrorEnvelope>();
            obj.Error.Should().BeAssignableTo <StripeError>();
            obj.Error.Type.Should().Be("some type");
            obj.Error.Message.Should().Be("I am a message");
        }