public String[] GetNextGridResponses(int pollID)
        {
            var pollRepository = new PollRepository(session);
            var poll = pollRepository.GetPollByID(pollID);
            var keypads = from item in poll.gridResponses
                          select item.DeviceID;
            var responses = new List<String>();
            responses.AddRange(keypads);
            poll.gridResponses = null;
            pollRepository.UpdatePoll(poll);

            return responses.ToArray<String>();
        }