Here is my basic example:

```
class Foo {

    public $toy = "car";

    public function run() {
        $this->toy = "train";
        $bar = new Bar();
        $bar->run();
    }   
}

class Bar extends Foo {
    public function run() {
        echo $this->toy;
    }
}

$foo = new Foo();
$foo->run();

```

For some reason it will always echo car not train. What is the reason for this?