public static function teacher_get_group_grades($course_id, $group_id, $search)
 {
     global $CFG, $DB;
     $params = self::validate_parameters(self::teacher_get_group_grades_parameters(), array('course_id' => $course_id, 'group_id' => $group_id, 'search' => $search));
     $auth = new auth_plugin_joomdle();
     $return = $auth->teacher_get_group_grades($course_id, $group_id, $search);
     return $return;
 }