protected static function buildOutcomeResponse(AssessmentItemSession $itemSession)
 {
     $stateOutput = new taoQtiCommon_helpers_PciStateOutput();
     foreach ($itemSession->getOutcomeVariables(false) as $var) {
         $stateOutput->addVariable($var);
     }
     $output = $stateOutput->getOutput();
     return $output;
 }