eZ\Publish\Core\REST\Common\Input\Handler\Xml::parseFieldTypeHash PHP Method

    protected function parseFieldTypeHash(\DOMElement $domElement)
    {
        $result = $this->parseFieldTypeValues($domElement->childNodes);
        if (is_array($result) && empty($result)) {
            // No child values means null
            return null;
        }
        return $result;
    }