def METHOD_NAME(
    api_client, event, registration, signup, signup2
):
    registration.maximum_attendee_capacity = 2
    registration.waiting_list_capacity = 2
    registration.save()
    reservation = SeatReservationCode.objects.create(seats=1, registration=registration)
    reservation_data = {
        "seats": 3,
        "registration": registration.id,
        "code": reservation.code,
    }
    response = update_seats_reservation(api_client, reservation.id, reservation_data)
    assert response.status_code == status.HTTP_400_BAD_REQUEST
    assert (
        response.data["seats"][0]
        == "Not enough capacity in the waiting list. Capacity left: 2."
    )