public static void FillBooking(Booking booking, SqlDataReader reader)
        {
            int userId = reader.GetInt32(reader.GetOrdinal("UserId"));

            booking.UserId          = userId;
            booking.ReceiveMessages = reader.GetBoolean(reader.GetOrdinal("ReceiveMessages"));

            var fillInt = CreateFillSimpleType <int>("EventId");

            IEnumerable <SimpleType <int> > eventIds = DataBases
                                                       .Access <SimpleType <int> >(BaseNames.SikonDatabase, "BookedEvents")
                                                       .GetSelection(fillInt, BookingsController.PrimaryKeys(userId));

            booking.BookedEventsId = new HashSet <int>();
            foreach (SimpleType <int> simpleType in eventIds)
            {
                booking.BookedEventsId.Add(simpleType.Variable);
            }
        }