public static function get_lesson($lessonid, $password = '') {
        global $PAGE;

        $params = array('lessonid' => $lessonid, 'password' => $password);
        $params = self::validate_parameters(self::get_lesson_parameters(), $params);
        $warnings = array();

        list($lesson, $course, $cm, $context, $lessonrecord) = self::validate_lesson($params['lessonid']);

        $lessonrecord = self::get_lesson_summary_for_exporter($lessonrecord, $params['password']);
        $exporter = new lesson_summary_exporter($lessonrecord, array('context' => $context));

        $result = array();
        $result['lesson'] = $exporter->export($PAGE->get_renderer('core'));
        $result['warnings'] = $warnings;
        return $result;
    }