n?;

        let n = n?;

        for e in iter_adjacent(txn, channel, pos.inode_vertex(), f, EdgeFlags::all())? {

        for e in iter_adjacent(txn, channel, pos.inode_vertex(), f, f | EdgeFlags::BLOCK)? {

        Ok(Some(id))

        if id.is_empty() {
            Ok(None)
        } else {
            Ok(Some(id))
        }