public function addQuery($query, array $indexes)
    {
        $indexNames = '';
        foreach ($indexes as &$label) {
            if (isset($this->indexes[$label])) {
                $indexNames .= $this->indexes[$label] . ' ';
            }
        }

        if (!empty($indexNames)) {
            $this->sphinx->addQuery($query, $indexNames);
        }
    }