public decimal?Add(QoalaEntities context)
        {
            var outParameter = new ObjectParameter("OUT_ID_GEO", typeof(decimal));

            context.SP_INSERT_DEVICE_GEO_LOCATION(
                ID_DEVICE,
                LATITUDE,
                LONGITUDE,
                outParameter
                );

            if (outParameter.Value == DBNull.Value)
            {
                throw new CreateRecordException();
            }

            ID_DEVICE_GEO_LOCATION    = (Decimal)outParameter.Value;
            context.Entry(this).State = EntityState.Unchanged;

            Device device = DAO.Device.findById(context, ID_DEVICE);

            device.LAST_LATITUDE  = LATITUDE;
            device.LAST_LONGITUDE = LONGITUDE;
            device.UpdateLastLocation(context);

            return(ID_DEVICE_GEO_LOCATION);
        }