ExtensionDescriptor extensionDescriptor = new ExtensionDescriptor();

        XmlNode dom;
        try {
            XMLStreamReader reader = WstxInputFactory.newFactory().createXMLStreamReader(is);
            dom = XmlNodeStaxBuilder.build(reader);
        } catch (XMLStreamException e) {
            throw new IOException(e.getMessage(), e);
        }

        if (!"extension".equals(dom.getName())) {