Doctrine nested array hydration

Question

i've try to hydrate an nested array to entities.

The array looks something like this

<?php
    $arrData = array(
        'username' => 'test',
        'email' => '[e-mail]',
        'images' => array(
            array(
                'name' => 'test',
                'url' => 'http://url1.test'
            ),
            array(
                'name' => 'test',
                'url' => 'http://url1.test'
            )
        )
    );
?>

So how you can see, there is an one to many relation between user and images. So if what i want to do, is i want do hydrate them into an User entity something like this:

<?php
    $hydrator = new \DoctrineModule\Stdlib\Hydrator\DoctrineObject($objectManager);
    $user = $hydrator->hydrate($arrData, new \Application\Entity\User());
?>

So if i try this, i get an exception with

Doctrine\ORM\ORMException
The identifier id is missing for a query of Application\Entity\Image

What ive seen is, doctrine try to find some entry at the database, but i need to create a new entry.

The thing is, i want to hydrate REST data, so i dont define any form or fieldsets.

Does anyone have an idea?

regards