结果为啥会出现：跨裤，破球鞋，打扮 alex，哪里调用了 Sneakers 的 show 方法？ [ 2.0 版本 ]

<?php 
class Person
{   
    private $name;
    function __construct($name)
    {
        $this->name = $name;
    }

    public function show()
    {
        echo "打扮".$this->name."\n";
    }
}

class Finery
{
    protected $person;

    public function decorate($person)
    {
        $this->person = $person;
    }

    public function show()
    {
        if ($this->person != null)
        {
            $this->person->show();
        }
    }
}
class TShirts extends Finery
{
    public function show()
    {
        echo "大T恤\n";
        parent::show();
    }
}
class BigTrouser extends Finery
{
    public function show()
    {
        echo "跨裤\n";
        parent::show();
    }
}
class Sneakers extends Finery
{
    public function show()
    {
        echo "破球鞋\n";
        parent::show();
    }
}

$person = new Person("alex");
$sneakers = new Sneakers();
$bigTrouser = new BigTrouser();
$tShirts = new TShirts();

$sneakers->decorate($person);
$bigTrouser->decorate($sneakers);
$tShirts->decorate($bigTrouser);
$tShirts->show();