private function get_neighbour_links_html() : string {
        $forum = $this->forum;
        $coursemodule = $forum->get_course_module_record();
        $neighbours = forum_get_discussion_neighbours($coursemodule, $this->discussionrecord, $this->forumrecord);
        return $this->renderer->neighbouring_discussion_navigation($neighbours['prev'], $neighbours['next']);
    }