protected function _buildCountQuery($uri, $setup)
 {
     $query = new Erfurt_Sparql_Query2();
     $query->addProjectionVar(new Erfurt_Sparql_Query2_Var('resourceUri'));
     $query->setCountStar(true);
     $query->setDistinct();
     $query->addElements(NavigationHelper::getInstancesTriples($uri, $setup));
     // error logging
     $this->_owApp->logger->info('NavigationController: COUNTQUERY: ' . $query->__toString());
     //*/
     return $query;
 }