php - Using DOMDocument in Zendframework2

Question

I would like to use DOMDocument in ZendFramework 2 but I don't know how. My normal script (non-zf2) looks as follows:

<?php 
...
$response = $client->$webservice($variables);
$dom = new DOMDocument();
$dom->loadXML($response->$property);
return $dom;

And it works fine. But I want to use this in my ZendFramework 2 Application. But this line:

$dom = new DOMDocument();

gives me this error: Fatal error: Class 'Sols\Model\DOMDocument' not found in... I thought mayby I should use Zend\Dom\Query but that won't work either. How to be able to use the "standard" DOMDocument in ZendFramework2?

By the way, DOMDocument works fine on my server (if I don't use it within ZendFramework2)...

Thank you very much :-)