public function search(array $params)
    {
        $response = $this->requestAndResponse('SEARCH', $params);
        if (!$response) {
            return $response;
        }

        foreach ($response as $ids) {
            if ($ids[0] == 'SEARCH') {
                array_shift($ids);
                return $ids;
            }
        }
        return array();
    }