code: public function comment(RunnerServiceContext $context, $comment)
      {
          // prepare transmission Id for result server.
          $testSession = $context->getTestSession();
          $item = $testSession->getCurrentAssessmentItemRef()->getIdentifier();
          $occurrence = $testSession->getCurrentAssessmentItemRefOccurence();
          $sessionId = $testSession->getSessionId();
          $transmissionId = "${sessionId}.${item}.${occurrence}";
  
          /** @var DeliveryServerService $deliveryServerService */
          $deliveryServerService = $this->getServiceManager()->get(DeliveryServerService::SERVICE_ID);
          $resultStore = $deliveryServerService->getResultStoreWrapper($sessionId);
  
          $transmitter = new \taoQtiCommon_helpers_ResultTransmitter($resultStore);
  
          // build variable and send it.
          $itemUri = TestRunnerUtils::getCurrentItemUri($testSession);
          $testUri = $testSession->getTest()->getUri();
          $variable = new ResponseVariable('comment', Cardinality::SINGLE, BaseType::STRING, new QtismString($comment));
          $transmitter->transmitItemVariable($variable, $transmissionId, $itemUri, $testUri);
  
          return true;
      }
docs: Comment the test
  @param RunnerServiceContext $context
  @param string $comment
  @return bool