private function handleFilters(
            ExportInterface $export, 
            QueryBuilder $qb, 
            $data, 
            array $centers)
    {
        $filters = $this->retrieveUsedFilters($data);
                
        foreach($filters as $alias => $filter) {
            if ($this->isGrantedForElement($filter, $export, $centers) === false) {
                throw new UnauthorizedHttpException("You are not authorized to "
                        . "use the filter ".$filter->getTitle());
            }
            
            $formData = $data[$alias];

            $this->logger->debug('alter query by filter '.$alias, array(
                'class' => self::class, 'function' => __FUNCTION__
            ));
            $filter->alterQuery($qb, $formData['form']);

        }
    }