public function getAssessmentItemRefByIdentifier(\tao_models_classes_service_StorageDirectory $privateCompilationDirectory, $identifier)
    {
        $compilationDataService = $this->getServiceLocator()->get(CompilationDataService::SERVICE_ID);
        $filename = "adaptive-assessment-item-ref-${identifier}";
        
        return $compilationDataService->readPhpCompilationData(
            $privateCompilationDirectory,
            "${filename}.php",
            "${filename}"
        );
    }