return Collections.emptyList();
            }
        };
        ComponentUtil.register(requestHeaderService, RequestHeaderService.class.getCanonicalName());

        final SetOnce<Map<String, Object>> initParamMapSet = new SetOnce<>();
        WebConfig webConfig = new WebConfig();
        webConfig.setUserAgent(Constants.CRAWLING_USER_AGENT_PREFIX + "1.0" + Constants.CRAWLING_USER_AGENT_SUFFIX);

            if (logger.isDebugEnabled()) {
                logger.debug("nonce={}", nonce);
            }
            if (StringUtils.isEmpty(nonce) || !nonce.equals(stateData.getNonce())) {
                throw new SsoLoginException("could not validate nonce");
            }
        } catch (final SsoLoginException e) {
            throw e;
        } catch (final Exception e) {

    public void close() {
        if (runner != null) {
            try {
                client.admin()
                        .indices()
                        .prepareFlush()
                        .setForce(true)
                        .execute()
                        .actionGet(ComponentUtil.getFessConfig().getIndexIndicesTimeout());
            } catch (final Exception e) {