static function createShowInvisibleSQLString($useSettings, $fetchHidden = true)
 {
     $showInvisibleNodesCond = '';
     $showInvisible = $fetchHidden;
     if ($useSettings) {
         $showInvisible = eZContentObjectTreeNodeNoLanguage::showInvisibleNodes();
     }
     if (!$showInvisible) {
         $showInvisibleNodesCond = 'AND ezcontentobject_tree.is_invisible = 0';
     }
     return $showInvisibleNodesCond;
 }