public function handle_get_colSpec () {
        $url = new UrlHelper ();
        $filters = $url->get("filters_json", "[]");

        $params = array(
            'filters_json' => $filters
        );

        return array(
            'type' => 'json',
            'data' => array (
                'count' => $this->dataProvider->getRowCount($params),
                'schema' => $this->dataProvider->getSchema(),
                'columns' => $this->dataProvider->getSummaryColumns()
            )
        );
    }