public static function getJson()
{
return '{"id":"TestSample","number":"TestSample","type":"TestSample","expire_month":"123","expire_year":"123","start_month":"TestSample","start_year":"TestSample","cvv2":"TestSample","first_name":"TestSample","last_name":"TestSample","billing_country":"TestSample","billing_address":' . AddressTest::getJson() . ',"external_customer_id":"TestSample","status":"TestSample","card_product_class":"TestSample","valid_until":"TestSample","issue_number":"TestSample","links":' . LinksTest::getJson() . '}';
}