@Override
    public XStreamAlias addingService(ServiceReference<XStreamAlias> serviceReference) {

      Registry registry = RegistryUtil.getRegistry();

      XStreamAlias xStreamAlias = registry.getService(serviceReference);

      _xstreamAliases.put(xStreamAlias.getClazz(), xStreamAlias.getName());

      return xStreamAlias;
    }
    @Override
    public void removedService(
        ServiceReference<XStreamAlias> serviceReference, XStreamAlias xStreamAlias) {

      Registry registry = RegistryUtil.getRegistry();

      registry.ungetService(serviceReference);

      _xstreamAliases.remove(xStreamAlias.getClazz());
    }