Function reconstruct_subtree_root 

pub fn reconstruct_subtree_root<'a, R>(
    reader: &'a R,
    alg_id: u64,
    view: &'a AlgView,
    lo: u64,
    hi: u64,
    k: u64,
    kind: LogKind,
    store_mixed: bool,
) -> Pin<Box<dyn Future<Output = Result<(Vec<u8>, Vec<(u64, u32, Vec<u8>)>), R::Error>> + Send + 'a>>
where
    R: NodeReader + Sync + 'a,

Recursively resolve a subtree root over the read substrate and collect the mixed boundary nodes that must be persisted (used when reopening a frozen algorithm’s frontier). Returns (root, mixed_nodes) where mixed_nodes are (left, height, hash) triples.

Errors

Propagates Error from the node/leaf reads.