.ifPresent(s -> entry.put(new BasicAttribute(fessConfig.getLdapAttrSurname(), s)));
        OptionalUtil.ofNullable(user.getGivenName()).filter(StringUtil::isNotBlank)
                .ifPresent(s -> entry.put(new BasicAttribute(fessConfig.getLdapAttrGivenName(), s)));
        OptionalUtil.ofNullable(user.getMail()).filter(StringUtil::isNotBlank)

        return getSystemProperty(Constants.PURGE_BY_BOTS_PROPERTY, Constants.DEFAULT_PURGE_BY_BOTS);
    }

    default boolean hasNotification() {
        return StringUtil.isNotBlank(getNotificationTo()) || StringUtil.isNotBlank(getSlackWebhookUrls());
    }

    default void setSlackWebhookUrls(final String value) {
        setSystemProperty(Constants.SLACK_WEBHOOK_URLS_PROPERTY, value);
    }

        if (StringUtil.isNotBlank(username) && StringUtil.isNotBlank(password)) {
            builder.put(Constants.FESEN_USERNAME, username);
            builder.put(Constants.FESEN_PASSWORD, password);
        }
        final String authorities = fessConfig.getFesenHttpSslCertificateAuthorities();
        if (StringUtil.isNotBlank(authorities)) {

                boolean first2 = true;
                for (final Map.Entry<String, Object> entry : doc.entrySet()) {
                    final String name = entry.getKey();
                    if (StringUtil.isNotBlank(name) && entry.getValue() != null) {
                        if (!first2) {
                            buf.append(',');
                        } else {
                            first2 = false;