private static function _groupResponseFromFields(&$json, &$fields)
    {
        $result = new Api\GroupResult();
        $result->setChildGroups($fields->child_groups);
        $result->setGroupId($fields->id);
        $result->setSize($fields->size);
        $result->setCreatedAt(
            Deserialize::_dateTime($json, $fields->created_at)
        );
        $result->setModifiedAt(
            Deserialize::_dateTime($json, $fields->modified_at)
        );

        if (isset($fields->name)) {
            $result->setName($fields->name);
        }

        if (isset($fields->auto_update)) {
            $result->setAutoUpdate(
                Deserialize::_autoUpdateFromFields($fields->auto_update)
            );
        }

        return $result;
    }