private EntityManager em;
@Transactional(readOnly = false)
private void createDataUpdate(DataUpdate.UpdateType type, long guestId, Long apiKeyId, Long objectTypeId,
String deviceName, String[] channelNames, String addtionalInfo, Long start, Long end){
DataUpdate update = new DataUpdate();
update.type = type;
update.guestId = guestId;
update.apiKeyId = apiKeyId;
update.objectTypeId = objectTypeId;
if (channelNames != null){