if (requestHeader.isValid()) {
                requestHeaderList.add(new BasicHeader(requestHeader.getName(), requestHeader.getValue()));
            }
        }

        // do not redirect
        requestConfigBuilder.setRedirectsEnabled(getInitParameter(REDIRECTS_ENABLED, redirectsEnabled, Boolean.class));

        // cookie
        if (cookieSpec != null) {

            }
        } else {
            saveError(messages -> messages.addErrorsUnknownVersionForUpgrade(GLOBAL));
        }
        return redirect(getClass());
    }

    private void upgradeFrom13_0() {
        UpgradeUtil.addData(searchEngineClient, ".fess_config.scheduled_job", "label_updater",

    /**
     * Get the value for the key 'indexer.data.max.redirect.count'. <br>
     * The value is, e.g. 10 <br>
     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     */
    String getIndexerDataMaxRedirectCount();

    /**
     * Get the value for the key 'indexer.data.max.redirect.count' as {@link Integer}. <br>
     * The value is, e.g. 10 <br>