}
        return url.replaceFirst("\\{lang\\}", target == null ? "EN" : target);
    }

    public String getHelpLink(final String name) {
        final String url = ComponentUtil.getFessConfig().getOnlineHelpBaseLink() + name + "-guide.html";
        return getHelpUrl(url);
    }

    protected String getHelpUrl(final String url) {
        final Locale locale = ComponentUtil.getRequestManager().getUserLocale();

     * The value is, e.g. https://fess.codelibs.org/{lang}/{version}/admin/ <br>
     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     */
    String getOnlineHelpBaseLink();

    /**
     * Get the value for the key 'online.help.installation'. <br>
     * The value is, e.g. https://fess.codelibs.org/{lang}/{version}/install/install.html <br>