Oauth authentication about eightpointsguzzlebundle HOT 2 CLOSED

public function onPreTransaction(PreTransactionEvent $event)
    {
        $request     = $event->getTransaction();
        $serviceName = $event->getServiceName();
        if ($serviceName == $this->serviceName) {
            if (!$this->requestHelper->isOauth2TokenReceiveRequest($request)) {
                $request = $request->withHeader('Authorization', sprintf('Bearer %s', $this->accessTokenProvider->getAccessToken()->getToken()));
                $event->setTransaction($request);
            }
        }
    }

 // Handle the response form teh server.
                return $promise->then(
                        function (ResponseInterface $response) {
                        // Create hte Post Transaction event.
                        $postTransactionEvent = new PostTransactionEvent($response, $this->serviceName);
                        // Dispatch the event on the symfony event dispatcher.
                        $this->eventDispatcher->dispatch(GuzzleEvents::POST_TRANSACTION, $postTransactionEvent);
                        // Continue down the chain.
                        return $postTransactionEvent->getTransaction();
                    }, function (RequestException $e) {
                        $postTransactionEvent = new PostTransactionErrorEvent($e, $this->serviceName);
                        // Dispatch the event on the symfony event dispatcher.
                        $this->eventDispatcher->dispatch(GuzzleEvents::POST_TRANSACTION_ERROR, $postTransactionEvent);
                    }
                );