def METHOD_NAME(api_client, event, registration):
    reservation = SeatReservationCode.objects.create(seats=1, registration=registration)
    timestamp = reservation.timestamp
    reservation_data = {
        "seats": 2,
        "registration": registration.id,
        "code": reservation.code,
        "timestamp": localtime() + timedelta(minutes=15),
    }
    assert_update_seats_reservation(api_client, reservation.id, reservation_data)
    updated_reservation = SeatReservationCode.objects.get(id=reservation.id)
    assert updated_reservation.seats == 2
    assert updated_reservation.timestamp == timestamp