// Callableタスク(複数)を実行する
        final ExecutorService executor = Executors.newFixedThreadPool(numTasks);
        try {
            final List<Future<Integer>> futures = executor.invokeAll(tasks);
            for (final Future<Integer> future : futures) {
                future.get();
            }
        } catch (final InterruptedException e) {
            // no thing to do
        } catch (final ExecutionException e) {

    // return responseData;
    // }
    // }
    // return null;
    // }
    // });
    // }
    // List<Future<ResponseData>> futureList = executorService.invokeAll(list);
    // for (Future<ResponseData> future : futureList) {
    // ResponseData responseData = future.get();
    // if (responseData != null) {
    // System.out.println("status: "
    // + responseData.getHttpStatusCode()

    @Override
    public AdminClient admin() {
        return client.admin();
    }

    /**
     * Executes an index request.
     *
     * @param request The index request.
     * @return Future for the index response.
     */
    @Override
    public ActionFuture<IndexResponse> index(final IndexRequest request) {
        return client.index(request);
    }

    /**