PHP [closures] [override method runtime] How Improve this wrapp - php

Question

I wrote this code for override a object method:
class A{
public function foo(){
echo "foo";
}
}
$a = new A();
$a->foo = function(){
echo "don't work";
}
$a->foo();
but the above code doesn't work i tried use a Closure but it didn't work.
so i wrote this utility class in my project, the class work and it works as expected.
class Wrapper
{
public $wrapped;
private $binds;
private $obj;
public function __construct($obj)
{
$this->wrapped = true;
$this->obj = $obj;
$this->binds = [];
}
public function bind($name, $function){
$this->binds[$name] = \Closure::bind($function, $this->obj, get_class($this->obj));
}
public function __set($name, $value)
{
$this->obj->$name = $value;
}
public function __get($name)
{
if(property_exists($this, $name)){
return $this->$name;
}
return $this->obj->$name;
}
public function __isset($name)
{
return isset($this->obj->$name);
}
public function __unset($name)
{
unset($this->obj->$name);
}
public function __call($name, $arguments)
{
if (array_key_exists($name, $this->binds) ) {
return call_user_func_array($this->binds[$name], $arguments);
}
return call_user_func_array([$this->obj, $name], $arguments);
}
public static function __callStatic($name, $arguments)
{
return call_user_func_array([get_class($this->obj, $name), $name], $arguments);
}
}
but the above class is a dirty fix, so how i can use the closure class or other method for do the same thing?