public function links_to_other_redos($slot, moodle_url $baseurl) {
        $originalslot = $this->get_original_slot($slot);

        $qas = $this->all_question_attempts_originally_in_slot($originalslot);
        if (count($qas) <= 1) {
            return null;
        }

        $links = new mod_quiz_links_to_other_attempts();
        $index = 1;
        foreach ($qas as $qa) {
            if ($qa->get_slot() == $slot) {
                $links->links[$index] = null;
            } else {
                $url = new moodle_url($baseurl, array('slot' => $qa->get_slot()));
                $links->links[$index] = new action_link($url, $index,
                        new popup_action('click', $url, 'reviewquestion',
                                array('width' => 450, 'height' => 650)),
                        array('title' => get_string('reviewresponse', 'question')));
            }
            $index++;
        }
        return $links;
    }