Function ancestors_between 

pub fn ancestors_between(
    table_metadata: &TableMetadataRef,
    latest_snapshot_id: i64,
    oldest_snapshot_id: Option<i64>,
) -> impl Iterator<Item = SnapshotRef> + Send

Iterate starting from latest_snapshot_id (inclusive) to oldest_snapshot_id (exclusive).

Note: if oldest_snapshot_id is Some(id) but id is not actually an ancestor of latest_snapshot_id, the walk is never stopped and this yields all ancestors of latest_snapshot_id down to the root. Callers that treat oldest_snapshot_id as a lower bound must validate the lineage themselves.