/**
  * @param string[] $labels
  * @param string   $recache ignored
  *
  * @return EntityId[] a map of strings from $labels to the corresponding entity ID.
  */
 public function getPropertyIdsForLabels(array $labels, $recache = '')
 {
     $entityIds = array();
     foreach ($labels as $label) {
         $entity = $this->mockRepository->getPropertyByLabel($label, $this->languageCode);
         if ($entity !== null) {
             $entityIds[$label] = $entity->getId();
         }
     }
     return $entityIds;
 }