public function testError()
 {
     $sale = new Request();
     $sale->unsetField("login");
     $sale->unsetField("tran_key");
     $sale->unsetField("delim_data");
     $sale->unsetField("version");
     $sale->unsetField("relay_response");
     $response = $sale->authorizeAndCapture();
     // An exception should have been thrown.
     $this->assertFalse($response->approved);
     $this->assertTrue($response->error);
 }