@Override
public void asyncCloseSubscription(final TopicSubscriber topicSubscriber,
final Callback<ResponseBody> callback,
final Object context) {
final ActiveSubscriber ss = getActiveSubscriber(topicSubscriber);
if (null == ss || null == hChannel) {
logger.debug("No subscription {} found when closing its subscription from {}.",
va(topicSubscriber, hChannel));
callback.operationFinished(context, (ResponseBody)null);
return;