use std::convert::TryInto; use crate::pack::fixture_path; #[test]fn encode_decode_roundtrip() -> crate::Result {    let buf = std::fs::read(fixture_path(        "objects/pack/pack-11fdfa9e156ab73caae3b6da867192221f2089c2.pack",    ))?;    let expected_encoded_header = &buf[..12];    let (version, num_objects) = git_pack::data::header::decode(expected_encoded_header.try_into()?)?;    let actual_encoded_header = git_pack::data::header::encode(version, num_objects);    assert_eq!(actual_encoded_header, expected_encoded_header);    Ok(())}