public function testOperations()
{
$payment = PaymentTest::createNewPayment();
$payment->create();
$transactions = $payment->getTransactions();
$resources = $transactions[0]->getRelated_resources();
$saleId = $resources[0]->getSale()->getId();
$sale = Sale::get($saleId);
$this->assertNotNull($sale);
$refund = new Refund();
$refund->setAmount(AmountTest::createAmount());
$sale->refund($refund);
$this->setExpectedException('\\InvalidArgumentException');
$sale->refund(NULL);
}
