public static function getRouteFilter()
    {
        $opt = new ezpExtensionOptions();
        $opt->iniFile = 'rest.ini';
        $opt->iniSection = 'RouteSettings';
        $opt->iniVariable = 'RouteSettingImpl';

        $routeSecurityFilterInstance = eZExtension::getHandlerClass( $opt );

        if ( ! $routeSecurityFilterInstance instanceof self )
        {
            throw new ezpRestRouteSecurityFilterNotFoundException();
        }

        return $routeSecurityFilterInstance;
    }