public function clon(&$object=null) {
    list($object) = self::_wrapArgs(func_get_args(), 1);
    
    $clone = null;
    if(is_array($object)) $clone = (array) clone (object) $object;
    elseif(!is_object($object)) $clone = $object;
    elseif(!$clone) $clone = clone $object;
    
    // shallow copy object
    if(is_object($clone) && count($clone) > 0) {
      foreach($clone as $k=>$v) {
        if(is_array($v) || is_object($v)) $clone->$k =& $object->$k;
      }
    }
    
    // shallow copy array
    elseif(is_array($clone) && count($clone) > 0) {
      foreach($clone as $k=>$v) {
        if(is_array($v) || is_object($v)) $clone[$k] =& $object[$k];
      }
    }
    return self::_wrap($clone);
  }