protected function unmarshall(DOMElement $element)
    {
        if (($responseIdentifier = $this->getDOMElementAttributeAs($element, 'responseIdentifier')) !== null) {

            $frag = $element->ownerDocument->createDocumentFragment();
            $element = $element->cloneNode(true);
            $frag->appendChild($element);
            $xmlString = $frag->ownerDocument->saveXML($frag);

            $component = new CustomInteraction($responseIdentifier, $xmlString);
            $this->fillBodyElement($component, $element);
        }

        return $component;
    }