public static function get_instance_info($instanceid) {
        global $DB, $CFG;

        require_once($CFG->libdir . '/enrollib.php');

        $params = self::validate_parameters(self::get_instance_info_parameters(), array('instanceid' => $instanceid));

        // Retrieve self enrolment plugin.
        $enrolplugin = enrol_get_plugin('self');
        if (empty($enrolplugin)) {
            throw new moodle_exception('invaliddata', 'error');
        }

        self::validate_context(context_system::instance());

        $enrolinstance = $DB->get_record('enrol', array('id' => $params['instanceid']), '*', MUST_EXIST);
        $course = $DB->get_record('course', array('id' => $enrolinstance->courseid), '*', MUST_EXIST);
        if (!core_course_category::can_view_course_info($course) && !can_access_course($course)) {
            throw new moodle_exception('coursehidden');
        }

        $instanceinfo = (array) $enrolplugin->get_enrol_info($enrolinstance);
        if (isset($instanceinfo['requiredparam']->enrolpassword)) {
            $instanceinfo['enrolpassword'] = $instanceinfo['requiredparam']->enrolpassword;
        }
        unset($instanceinfo->requiredparam);

        return $instanceinfo;
    }