public static function getDefaultOptValue(Kwf_Component_Data $data)
 {
     $ret = $data->getBaseProperty('statistics.defaultOptValue');
     if ($ret != self::OPT_IN && $ret != self::OPT_OUT) {
         throw new Kwf_Exception('statistics.defaultOptValue must be ' . self::OPT_IN . ' or ' . self::OPT_OUT);
     }
     return $ret;
 }