private function send_qtype_files($qtype, $oldctxid, $newctxid, $progress) {
        if (!isset($this->qtypecomponentscache[$qtype])) {
            $this->qtypecomponentscache[$qtype] = backup_qtype_plugin::get_components_and_fileareas($qtype);
        }
        $components = $this->qtypecomponentscache[$qtype];
        foreach ($components as $component => $fileareas) {
            foreach ($fileareas as $filearea => $mapping) {
                restore_dbops::send_files_to_pool($this->get_basepath(), $this->get_restoreid(), $component, $filearea,
                        $oldctxid, $this->task->get_userid(), $mapping, null, $newctxid, true, $progress);
            }
        }
    }