connect(con -> {
            final RequestProcessor processor = new RequestProcessor(encoding, threshold);
            processor.accept(con);
            try (final CurlResponse res = processor.getResponse()) {
                actionListener.accept(res);
            } catch (final IOException e) {
                exceptionListener.accept(e);
            }
        }, exceptionListener);
    }

        searchEngineClient.flushConfigFiles(() -> {
            final String docIndex = fessConfig.getIndexDocumentUpdateIndex();
            searchEngineClient.admin().indices().prepareClose(docIndex).execute(ActionListener.wrap(res -> {
                logger.info("Close {}", docIndex);
                searchEngineClient.admin().indices().prepareOpen(docIndex).execute(