public PaymentSource toClass(string json)
        {
            PaymentSource payment_source = JsonConvert.DeserializeObject <PaymentSource>(json, new JsonSerializerSettings
            {
                NullValueHandling = NullValueHandling.Ignore
            });

            return(payment_source);
        }
        public PaymentSource update(string data)
        {
            PaymentSource payment_source = this.toClass(this.toObject(this.update("/customers/" + this.parent_id + "/payment_sources/" + this.id, data)).ToString());

            return(payment_source);
        }