The API returns a 304 when there is no change since the last request. In these cases the correct behaviour is to continue to use the previous response. If the most recent status was "UpdatesPending" then you can be sure that subsequent polls will return a 200 response. If the 304 is returned on the first poll, that means the session has not been fully initialized. In this case, poll again 1 second later.
What should I do when I receive a 304 not modified?
