public XStreamExtensionProvider(String elementName, Class<?>... classes) {
this.elementName = elementName;
this.namespace = PacketExtensionUtils.NAMESPACE;
xstream = new XStream();
xstream.registerConverter(new IPathConverter());
xstream.processAnnotations(XStreamPacketExtension.class);
xstream.processAnnotations(classes);
xstream.alias(elementName, XStreamPacketExtension.class);
ProviderManager providerManager = ProviderManager.getInstance();