// Un-registering from the Conference.
Profile profile = getProfileFromUser(user);
if (profile.getConferenceKeysToAttend().contains(websafeConferenceKey)) {
profile.unregisterFromConference(websafeConferenceKey);
conference.giveBackSeats(1);
ofy().save().entities(profile, conference).now();
return new WrappedBoolean(true);
} else {
return new WrappedBoolean(false, "You are not registered for this conference");
}