Image destructor issue

gistfile1.php

<?php

class Imagine
{
    function open($path)
    {
        return new Image(new \Gmagick($path));
    }
}

class Layers implements Countable
{
    private $resource;

    function __construct(\Gmagick $resource)
    {
        $this->resource = $resource;
    }

    function count()
    {
        return $this->resource->getnumberimages();
    }
}

class Image
{
    private $resource;
    public static $destructorActivated = false;

    function __construct(\Gmagick $resource)
    {
        $this->resource = $resource;
    }

    function __destruct()
    {
        if(self::$destructorActivated) {
            $this->resource->clear();
            $this->resource->destroy();
        }
    }

    function layers()
    {
        return new Layers($this->resource);
    }
}

$imageFile = 'image.gif';

// everything alright
$imagine = new Imagine();
$image = $imagine->open($imageFile);
echo sprintf("image has %d layers\n", count($image->layers()));

// everything alright
$imagine = new Imagine();
echo sprintf("image has %d layers\n", count($imagine->open($imageFile)->layers()));

// changing configuration
Image::$destructorActivated = true;

// everything alright
$imagine = new Imagine();
$image = $imagine->open($imageFile);
echo sprintf("image has %d layers\n", count($image->layers()));

// This fails, will print "image has 0 layers"
$imagine = new Imagine();
echo sprintf("image has %d layers\n", count($imagine->open($imageFile)->layers()));

how about this:

<?php

class Layers
{
    public function __construct(Image $image, \Gmagick $resource)
    {
        $this->image = $image; // just a trick to preserve image reference, to prevent it from being garbage collected until we're done with layers object
        $this->resource = $resource;
    }
}