public function extra_horizontal_navigation() {
        // Horizontal navigation for question bank.
        if ($questionnode = $this->page->settingsnav->find("questionbank", \navigation_node::TYPE_CONTAINER)) {
            if ($children = $questionnode->children) {
                $tabs = [];
                foreach ($children as $key => $node) {
                    $tabs[] = new \tabobject($node->key, $node->action, $node->text);
                }
                $active = $questionnode->find_active_node()->key;
                return \html_writer::div(print_tabs([$tabs], $active, null, null, true), 'questionbank-navigation');
            }
        }
        return '';
    }