PHP Decode

--TEST--
SPL: SplObjectStorage
--FILE--
<?php

class MyObjectStorage extends SplObjectStorage
{
    function rewind(): void
    {
        echo __METHOD__ . "()\n";
        parent::rewind();
    }

    function valid(): bool
    {
        echo __METHOD__ . "(" . (parent::valid() ? 1 : 0) . ")\n";
        return parent::valid();
    }

    function key(): int
    {
        echo __METHOD__ . "(" . parent::key() . ")\n";
        return parent::key();
    }

    function current(): object
    {
        echo __METHOD__ . "(" . parent::current()->getName() . ")\n";
        return parent::current();
    }

    function next(): void
    {
        echo __METHOD__ . "()\n";
        parent::next();
    }
}

class ObserverImpl implements SplObserver
{
    protected $name = '';

    function __construct($name = 'obj')
    {
        $this->name = '$' . $name;
    }

    function update(SplSubject $subject): void
    {
        echo $this->name . '->' . __METHOD__ . '(' . $subject->getName() . ");\n";
    }

    function getName()
    {
        return $this->name;
    }
}

class SubjectImpl implements SplSubject
{
    protected $name = '';
    protected $observers;

    function __construct($name = 'sub')
    {
        $this->observers = new MyObjectStorage;
        $this->name = '$' . $name;
    }

    function attach(SplObserver $observer): void
    {
        echo $this->name . '->' . __METHOD__ . '(' . $observer->getName() . ");\n";
        $this->observers->attach($observer);
    }

    function detach(SplObserver $observer): void
    {
        echo $this->name . '->' . __METHOD__ . '(' . $observer->getName() . ");\n";
        $this->observers->detach($observer);
    }

    function count(): int
    {
        return $this->observers->count();
    }

    function notify(): void
    {
        echo $this->name . '->' . __METHOD__ . "();\n";
        foreach($this->observers as $key => $observer)
        {
            $observer->update($this);
        }
    }

    function getName()
    {
        return $this->name;
    }

    function contains($obj)
    {
        return $this->observers->contains($obj);
    }
}

$sub = new SubjectImpl;

$ob1 = new ObserverImpl("ob1");
$ob2 = new ObserverImpl("ob2");
$ob3 = new ObserverImpl("ob3");

var_dump($sub->contains($ob1));
$sub->attach($ob1);
var_dump($sub->contains($ob1));
$sub->attach($ob1);
$sub->attach($ob2);
$sub->attach($ob3);
var_dump($sub->count());

$sub->notify();

$sub->detach($ob3);
var_dump($sub->count());

$sub->notify();

$sub->detach($ob2);
$sub->detach($ob1);
var_dump($sub->count());

$sub->notify();

$sub->attach($ob3);
var_dump($sub->count());

$sub->notify();

?>
--EXPECT--
bool(false)
$sub->SubjectImpl::attach($ob1);
bool(true)
$sub->SubjectImpl::attach($ob1);
$sub->SubjectImpl::attach($ob2);
$sub->SubjectImpl::attach($ob3);
int(3)
$sub->SubjectImpl::notify();
MyObjectStorage::rewind()
MyObjectStorage::valid(1)
MyObjectStorage::current($ob1)
MyObjectStorage::key(0)
$ob1->ObserverImpl::update($sub);
MyObjectStorage::next()
MyObjectStorage::valid(1)
MyObjectStorage::current($ob2)
MyObjectStorage::key(1)
$ob2->ObserverImpl::update($sub);
MyObjectStorage::next()
MyObjectStorage::valid(1)
MyObjectStorage::current($ob3)
MyObjectStorage::key(2)
$ob3->ObserverImpl::update($sub);
MyObjectStorage::next()
MyObjectStorage::valid(0)
$sub->SubjectImpl::detach($ob3);
int(2)
$sub->SubjectImpl::notify();
MyObjectStorage::rewind()
MyObjectStorage::valid(1)
MyObjectStorage::current($ob1)
MyObjectStorage::key(0)
$ob1->ObserverImpl::update($sub);
MyObjectStorage::next()
MyObjectStorage::valid(1)
MyObjectStorage::current($ob2)
MyObjectStorage::key(1)
$ob2->ObserverImpl::update($sub);
MyObjectStorage::next()
MyObjectStorage::valid(0)
$sub->SubjectImpl::detach($ob2);
$sub->SubjectImpl::detach($ob1);
int(0)
$sub->SubjectImpl::notify();
MyObjectStorage::rewind()
MyObjectStorage::valid(0)
$sub->SubjectImpl::attach($ob3);
int(1)
$sub->SubjectImpl::notify();
MyObjectStorage::rewind()
MyObjectStorage::valid(1)
MyObjectStorage::current($ob3)
MyObjectStorage::key(0)
$ob3->ObserverImpl::update($sub);
MyObjectStorage::next()
MyObjectStorage::valid(0)