Function create_hashes 

pub fn create_hashes<Wo, We>(
    path: &Path,
    ignored_files: BTreeSet<String>,
    algo: Algorithm,
    depth: Option<usize>,
    follow_symlinks: bool,
    jobs: usize,
    pb_out: Wo,
    pb_err: &mut We,
) -> BTreeMap<String, String>
where
    Wo: Write,
    We: Write,

Create subpath->hash mappings for a given path using a given algorithm up to a given depth.