Function capture_mountinfo_identity_order_keeping 

pub fn capture_mountinfo_identity_order_keeping(
    keep: &BTreeSet<u64>,
) -> Result<Vec<u64>, Error>

capture_mountinfo_identity_order, keeping every row whose mount ID is in keep (the rows a container mount table shows) whatever its name: a mount Hermit installed is never dropped by the seed filter, so a table showing it validates against the captured order.