public void merge(RoutingContext ctx) {
            Reply reply = new EmptyReply();
            reply.addError(new Error(ErrorCode.FATAL_ERROR,
                                     "Merge should not be called when select() sets a reply."));
            ctx.setReply(reply);
        }
@author havardpe
@author Simon Thoresen Hult
messagebus/src/test/java/com/yahoo/messagebus/routing/RoutingTestCase.java