/// Because the TryFrom implementations don't return proper errors/// on failure#[derive(Debug, thiserror::Error)]enum Error {    #[error("")]    TryFromError,} macro_rules! round_trip {    ($owned:ty, $borrowed:ty, $( $files:literal ), +) => {        #[test]        fn round_trip() -> Result<(), Box<dyn std::error::Error>> {            use std::convert::TryFrom;            use std::io::Write;            use crate::fixture_bytes;            use git_object::{ObjectRef, Object, WriteTo};            use bstr::ByteSlice;             for input in &[                $( $files ),*            ] {                let input = fixture_bytes(input);                // Test the parse->borrowed->owned->write chain for an object kind                let mut output = Vec::new();                let item = <$borrowed>::from_bytes(&input)?;                item.write_to(&mut output)?;                assert_eq!(output.as_bstr(), input.as_bstr());                 let item: $owned = item.into();                output.clear();                item.write_to(&mut output)?;                assert_eq!(output.as_bstr(), input.as_bstr());                 // Test the parse->borrowed->owned->write chain for the top-level objects                let item = ObjectRef::from(<$borrowed>::from_bytes(&input)?);                output.clear();                item.write_to(&mut output)?;                assert_eq!(output.as_bstr(), input.as_bstr());                 let item: Object = item.into();                output.clear();                item.write_to(&mut output)?;                assert_eq!(output.as_bstr(), input.as_bstr());                 // Test the loose serialisation -> parse chain for an object kind                let item = <$borrowed>::from_bytes(&input)?;                output.clear();                // serialise to a tagged loose object                let w = &mut output;                w.write_all(&item.loose_header())?;                item.write_to(w)?;                let parsed = ObjectRef::from_loose(&output)?;                let item2 = <$borrowed>::try_from(parsed).or(Err(super::Error::TryFromError))?;                assert_eq!(item2, item);            }            Ok(())        }    };} mod tag {    round_trip!(        git_object::Tag,        git_object::TagRef,        "tag/empty.txt",        "tag/no-tagger.txt",        "tag/whitespace.txt",        "tag/with-newlines.txt",        "tag/signed.txt"    );} mod commit {    round_trip!(        git_object::Commit,        git_object::CommitRef,        "commit/signed-whitespace.txt",        "commit/two-multiline-headers.txt",        "commit/mergetag.txt",        "commit/merge.txt",        "commit/signed.txt",        "commit/signed-singleline.txt",        "commit/signed-with-encoding.txt",        "commit/unsigned.txt",        "commit/whitespace.txt",        "commit/with-encoding.txt"    );} mod tree {    round_trip!(git_object::Tree, git_object::TreeRef, "tree/everything.tree");} mod blob {    // It doesn't matter which data we use - it's not interpreted.    round_trip!(git_object::Blob, git_object::BlobRef, "tree/everything.tree");}