protected static function fill_classmap_renames_cache() {
        global $CFG;

        self::$classmaprenames = array();

        self::load_renamed_classes("$CFG->dirroot/lib/");

        foreach (self::$subsystems as $subsystem => $fulldir) {
            self::load_renamed_classes($fulldir);
        }

        foreach (self::$plugins as $plugintype => $plugins) {
            foreach ($plugins as $pluginname => $fulldir) {
                self::load_renamed_classes($fulldir);
            }
        }
    }