Inheritance: implements Payum\Core\Action\ActionInterface
 /**
  * @test
  */
 public function shouldMarkUnknownIfAckNotRecognized()
 {
     $action = new GetPayoutStatusAction();
     $payout = ['ACK' => 'foo'];
     $request = new GetHumanStatus($payout);
     $action->execute($request);
     $this->assertTrue($request->isUnknown());
 }