code: public function getItemData(RunnerServiceContext $context, $itemRef)
      {
          if ($context instanceof QtiRunnerServiceContext) {
  
              return $this->loadItemData($itemRef, QtiJsonItemCompiler::ITEM_FILE_NAME);
  
          } else {
              throw new \common_exception_InvalidArgumentType(
                  'QtiRunnerService',
                  'getItemData',
                  0,
                  'oat\taoQtiTest\models\runner\QtiRunnerServiceContext',
                  $context
              );
          }
      }
docs: Gets definition data of a particular item
  @param RunnerServiceContext $context
  @param $itemRef
  @return mixed
  @throws \common_Exception