public static function uninstall($pluginname) {
        global $DB;

        list($a, $b) = core_component::normalize_component($pluginname);
        if (empty($b) || $a === 'core') {
            throw new coding_exception('Core component can not be uninstalled');
        }
        $component = $a . '_' . $b;

        core_tag_tag::delete_instances($component);

        $DB->delete_records('tag_area', array('component' => $component));
        $DB->delete_records('tag_coll', array('component' => $component));
        cache::make('core', 'tags')->delete_many(array('tag_area', 'tag_coll'));
    }