Function get_node_hash 

pub async fn get_node_hash<R: NodeReader>(
    reader: &R,
    view: &AlgView,
    alg_id: u64,
    left: u64,
    height: u32,
    arity: u64,
) -> Result<Vec<u8>, R::Error>

Retrieve a node hash from the read substrate, or return the algorithm’s null constant if the coordinate’s range carries no active leaf.

Errors

Returns Error::Read on a backend error, or Error::Corrupted if a stored node has the wrong digest width or an active range is missing its node.