Function encode_span 

pub fn encode_span(
    commit: Hash,
    offset: u64,
    len: u64,
    anchor: &[u8],
    chunks: &[&[u8]],
) -> Vec<u8> 

Encode an MKDS v1 container from already encoded MKDP v2 bundles.

Encoding does not authenticate or validate the supplied bundles. Callers must verify the result against a trusted commit id before using it.