Sonata\Component\Payment\TransactionInterface::addInformation PHP Method

    public function addInformation($message);

 /**
  * {@inheritdoc}
  */
 public function isCallbackValid(TransactionInterface $transaction)
 {
     if (!$transaction->getOrder()) {
         return false;
     }
     if ($transaction->get('check') == $this->generateUrlCheck($transaction->getOrder())) {
         return true;
     }
     $transaction->setState(TransactionInterface::STATE_KO);
     $transaction->setStatusCode(TransactionInterface::STATUS_WRONG_CALLBACK);
     $transaction->addInformation('The callback is not valid');
     return false;
 }