fn make_trainset_by_direction<'a>(
downwards: bool,
trips_iter: impl Iterator<Item = TripQueryItem<'a, 'a>>,
stops: &[Entity],
class_map: &EntityHashMap<usize>,
entry_q: &Query<'_, '_, EntryQuery>,
parent_station_or_station: &Query<'_, '_, ParentStationOrStation>,
) -> Structure<'static>