public static function getJson()
{
return '{"reference_id":"TestSample","amount":' . AmountTest::getJson() . ',"payee":' . PayeeTest::getJson() . ',"description":"TestSample","note_to_payee":"TestSample","custom":"TestSample","invoice_number":"TestSample","soft_descriptor":"TestSample","soft_descriptor_city":"TestSample","payment_options":' . PaymentOptionsTest::getJson() . ',"item_list":' . ItemListTest::getJson() . ',"notify_url":"http://www.google.com","order_url":"http://www.google.com","external_funding":' . ExternalFundingTest::getJson() . ',"type":"TestSample"}';
}