public static function location_error_not_found($not_found_page_url = null)
 {
     if (!$not_found_page_url) {
         $not_found_page_url = ZPHP::get_actual_uri();
     }
     $not_found_page_control_classname = ZPHP::get_config('redirect_control_special_pages_not_found_page_control');
     if ($not_found_page_control_classname) {
         $not_found_page_control = ClassHelper::create_instance($not_found_page_control_classname);
     } else {
         $not_found_page_control = null;
     }
     header("HTTP/1.0 404 Not Found");
     if ($not_found_page_control) {
         $not_found_page_control->out();
     }
     die;
 }