public function testPayWithSavedCard()
{
$this->setMockHttpResponse('RestCreateCardSuccess.txt');
$response = $this->gateway->createCard($this->options)->send();
$cardRef = $response->getCardReference();
$this->setMockHttpResponse('RestPurchaseSuccess.txt');
$response = $this->gateway->purchase(array('amount' => '10.00', 'cardReference' => $cardRef))->send();
$this->assertTrue($response->isSuccessful());
$this->assertEquals('44E89981F8714392Y', $response->getTransactionReference());
$this->assertNull($response->getMessage());
}