/**
  * @inheritDoc
  */
 public function prepareOnlineLocation(Page $page, UserOnline $user)
 {
     if ($user->pageObjectID !== null) {
         ViewableEntryRuntimeCache::getInstance()->cacheObjectID($user->pageObjectID);
     }
 }
 /**
  * @inheritDoc
  */
 public function isVisible($objectID = null)
 {
     return ViewableEntryRuntimeCache::getInstance()->getObject($objectID)->canRead();
 }