So the server always returns a JSON document, but if there's no user associated with the session it'll send back a non-empty error?

Do we want to log these errors?

What does the server return for the username when there is no user associated with the session token? It might be more obvious to check `} else if authResponse.UserName == "" }` (this way confused me a bit because you're checking the "error" condition already above, so I was wondering why you were checking it twice until I figured it out).