Php runkit_import和最终类

I read here: http://osdir.com/ml/php.phpunit.user/2008-05/msg00009.html that changing a class final behaviour may be changed with runkit - I just cant see the way how.

EDIT: dont -1 me pls, I checked the runkit_import() function and also the http://php.net/manual/en/runkit.constants.php still cant find the way

It's of... limited use. An illustration:

final class Foo {
    protected $var = '456';
    function doSomething(){
        return '123';
    }
    function getVar(){
        return $this->var;
    }
}

class Bar {

}
runkit_class_adopt('Bar','Foo');

$d = new Bar();
var_dumP($d->doSomething());
//string(3) "123"
var_dumP($d->getVar());
//PHP Notice:  Undefined property: Bar::$var in .... on line 10
//NULL

You're usually better of writing a Decorator for final classes (or removing the final from the source).