VOID response type can be replaced with empty generated method.

[asimarslan]

Instead of

    public static XCodec.ResponseParameters decodeResponse(ClientMessage clientMessage) {
        ClientMessage.ForwardFrameIterator iterator = clientMessage.frameIterator();
        ResponseParameters response = new ResponseParameters();
        //empty initial frame
        iterator.next();
        return response;
    }

we can just leave this method empty or even not generate the method.