prototype-based oop in php

prototype.php

<?
namespace prototype;
class Klass{ 
    public static function create($constructor){
        return new KlassEntity($constructor);
    }
}
class KlassEntity {
    public $prototype;
    private $constructor;
    public function __construct($constructor){
        $this->constructor = $constructor;
        $this->prototype = new \StdClass;
    }   
    public function create(){
        return new Instance(
            $this->prototype, $this->constructor, func_get_args());
    }       
    public function bindTo($target){
        return $this->constructor->bindTo($target);
    }   
    public function prototype($kvs){
        foreach($kvs as $k => $v){
            $this->prototype->$k = $v;
        }
    }   
}       
class Instance {
    private $prototype;
    public function __construct($prototype, $constructor, $args){
        $this->prototype = $prototype;
        call_user_func_array($constructor->bindTo($this), $args);
    }       
    public function __get($key){
        return $this->prototype->$key;
    }       
    public function __call($method, $args){
        $callee = $this->$method->bindTo($this);
        return call_user_func_array($callee, $args);
    }   
}

TestPrototype.php

<?
include_once 'prototype.php';
use Prototype\Klass;

class TestPrototype extends PHPUnit_Framework_TestCase{

    public function test_sample(){
        $Person = Klass::create(function($first, $last){
            $this->_first = $first;
            $this->_last = $last;
        });
        $Person->prototype([
            'getFullname' => function(){
                return $this->_first . " " . $this->_last;
            },
            'getFirstname' => function(){
                return $this->_first;
            },
        ]);
        $john = $Person->create('John', 'Smith');
        $john->getLastname = function(){
            return $this->_last;
        };
        $this->assertSame('Smith', $john->getLastname());
        $this->assertSame('John Smith', $john->getFullname());

        $inherit = function($parent){
            $child = Klass::create(function() use($parent){
                call_user_func_array(
                    $parent->bindTo($this), func_get_args());
            });
            $tmp = Klass::create(function(){});
            $tmp->prototype = $parent->prototype;
            $child->prototype = $tmp->create();
            return $child;
        };
        $Person2 = $inherit($Person);
        $john2 = $Person2->create('John2', 'Smith');
        $this->assertSame('John2 Smith', $john2->getFullname());
    }
}