Is it OK:
````java
private void checkReuse(AbstractReplyProducingMessageHandler replyHandler) {
		Assert.isTrue(!referencedReplyProducers.contains(targetObject),
				"An AbstractReplyProducingMessageHandler may only be referenced once (" +
				replyHandler.getComponentName() + ") - use scope=\"prototype\"");
		referencedReplyProducers.add(replyHandler);
	}
````
Suppose this method should use `referencedReplyProducers.contains(replyHandler)` or just relies on `this.targetObject`.
Or this method should be eliminated at all.

Everything other - LGTM!
Waiting for reply and ready to merge