@Named("websafeConferenceKey")
final String websafeConferenceKey)
throws UnauthorizedException, NotFoundException, ForbiddenException, ConflictException {
// If not signed in, throw a 401 error.
if (user == null) {
throw new UnauthorizedException("Authorization required");
}
WrappedBoolean result = ofy().transact(new Work<WrappedBoolean>() {
@Override
public WrappedBoolean run() {