function __construct($steam_object = FALSE)
 {
     self::$PATH = PATH_EXTENSIONS . "units_routeplaner/";
     self::$DISPLAY_NAME = gettext("Routeplaner");
     self::$DISPLAY_DESCRIPTION = gettext("You can use this unit type for routeplaning a term paper as part of your course. The creation dialog lets you choose a project name, further description of the project and start- and endgateway for the routeplan.");
     parent::__construct(PATH_EXTENSIONS . "units_routeplaner.xml", $steam_object);
     $this->set_action_permissions(PERMISSION_ACTION_EDIT | PERMISSION_ACTION_DELETE);
 }