Rebinding $this

class foo {
  public function getClosure() {
    return function() {
      echo $this->hello;
      $this->world();
    };
  }
}

class bar {
  public $hello = "Hello ";
  private function world() { echo "World"; }
}

$foo = new Foo();
$closure - $foo->getClosure();
$bar = new Bar();

$newClosure = $closure->bindTo($bar);
$newClosure();