public static function teacher_get_course_grades($id, $search)
 {
     global $CFG, $DB;
     $params = self::validate_parameters(self::teacher_get_course_grades_parameters(), array('id' => $id, 'search' => $search));
     $auth = new auth_plugin_joomdle();
     $return = $auth->teacher_get_course_grades($id, $search);
     return $return;
 }