Preconditions.checkArgument(req.getVersion() != 0,
// NOTE(ohler): In Google Wave, there were security concerns around
// creating objects by submitting deltas against version 0. I'm not
// sure Walkaround has the same problems, but let's disallow it anyway.
"Can't create objects with mutateObject()");
ServerMutateResponse response = defaultProcessor.mutateObject(req);
MutateResult result = new MutateResult(response.getResultingVersion());
if (response.getBroadcastData() != null) {
messageRouter.publishMessages(objectId, response.getBroadcastData());
}
return result;
}