public function getValue($name) {
    // return pk values as they are parts of the oid
    $mapper = ObjectFactory::getInstance('persistenceFacade')->getMapper($this->getType());
    $pkNames = $mapper->getPkNames();
    for ($i=0, $count=sizeof($pkNames); $i<$count; $i++) {
      if ($name == $pkNames[$i]) {
        $ids = $this->oid->getId();
        return $ids[$i];
      }
    }
    return $this->__call(__FUNCTION__, [$name]);
  }