class Test: Object {
  dynamic DBus.Object iservice;  

  construct {
    iservice.Signal += _signal_handler;
  }

  private void _signal_handler (dynamic DBus.Object iservice) {
    
  }
}

dbus_g_proxy_connect_signal (obj, signal_name, handler, data, NULL);

static void _test_signal_handler (Test* self, DBusGProxy* iservice) {
	g_return_if_fail (IS_TEST (self));
	g_return_if_fail (DBUS_IS_G_PROXY (iservice));
}