public URLStreamHandlerTracker(ModuleContext context) {
tracker = new ServiceTracker<URLStreamHandler, URLStreamHandler>(context, URLStreamHandler.class, null) {
@Override
public URLStreamHandler addingService(ServiceReference<URLStreamHandler> sref) {
URLStreamHandler handler = super.addingService(sref);
String protocol = getRequiredProtocol(sref);
URLStreamHandlerProxy proxy = handlers.get(protocol);
if (proxy == null) {
proxy = new URLStreamHandlerProxy(sref, handler);
handlers.put(protocol, proxy);