code: protected function getItemData($itemIdentifier)
      {
          $serviceContext = $this->getServiceContext();
          $itemRef = $this->getRunnerService()->getItemHref($serviceContext, $itemIdentifier);
          $itemData = $this->getRunnerService()->getItemData($serviceContext, $itemRef);
          $baseUrl = $this->getRunnerService()->getItemPublicUrl($serviceContext, $itemRef);
  
          $itemState = $this->getRunnerService()->getItemState($serviceContext, $itemIdentifier);
          if ($itemState === null || !count($itemState)) {
              $itemState = new stdClass();
          }
  
          return [
              'baseUrl' => $baseUrl,
              'itemData' => $itemData,
              'itemState' => $itemState,
              'itemIdentifier' => $itemIdentifier,
          ];
      }
docs: Create the item definition response for a given item
  @param string $itemIdentifier the item id
  @return array the item data
  @throws \common_Exception