Omnipay\PayPal\ExpressGatewayTest::testAuthorizeFailure PHP Method

    public function testAuthorizeFailure()
    {
        $this->setMockHttpResponse('ExpressPurchaseFailure.txt');
        $response = $this->gateway->authorize($this->options)->send();
        $this->assertFalse($response->isPending());
        $this->assertFalse($response->isSuccessful());
        $this->assertFalse($response->isRedirect());
        $this->assertNull($response->getTransactionReference());
        $this->assertSame('This transaction cannot be processed. The amount to be charged is zero.', $response->getMessage());
    }