public function display(core_backup_renderer $renderer) {

        $form = $this->initialise_stage_form();
        // A nasty hack follows to work around the sad fact that moodle quickforms
        // do not allow to actually return the HTML content, just to echo it.
        flush();
        ob_start();
        $form->display();
        $output = ob_get_contents();
        ob_end_clean();

        return $output;
    }