public function listShards(ListShardsRequest $request)
    {
        $params  = array();
        $headers = array();

        $project  = $request->getProject() ?: '';
        $logStore = $request->getLogStore() ?: '';

        $resource = '/logstores/' . $logStore . '/shards';
        list( $resp, $header ) = $this->send("GET", $project, null, $resource, $params, $headers);

        $requestId = isset ( $header ['x-log-requestid'] ) ? $header ['x-log-requestid'] : '';
        $resp      = $this->parseToJson($resp, $requestId);

        return new ListShardsResponse ($resp, $header);
    }