mod commit {    use std::cmp::Ordering;     use git_testtools::hex_to_id;     use crate::basic_repo;     #[test]    fn short_id() -> crate::Result {        let handle = basic_repo()?;        let commit = handle.head_commit()?;        assert_eq!(commit.short_id()?.cmp_oid(&commit.id), Ordering::Equal);        Ok(())    }     #[test]    fn tree() -> crate::Result {        let handle = basic_repo()?;        let commit = handle.head_commit()?;         assert_eq!(commit.tree()?.id, commit.tree_id().expect("id present"));        assert_eq!(            commit.tree_id().ok(),            Some(hex_to_id("21d3ba9a26b790a4858d67754ae05d04dfce4d0c"))        );        Ok(())    }     #[test]    fn decode() -> crate::Result {        let handle = basic_repo()?;        let commit = handle.head_commit()?;        assert_eq!(commit.decode()?.message, commit.message_raw()?);        assert_eq!(commit.decode()?.message(), commit.message()?);        assert_eq!(commit.decode()?.message, "c2\n");        Ok(())    }} #[test]fn object_ref_size_in_memory() {    assert_eq!(        std::mem::size_of::<git_repository::Object<'_>>(),        56,        "the size of this structure should not changed unexpectedly"    )} #[test]fn oid_size_in_memory() {    assert_eq!(        std::mem::size_of::<git_repository::Id<'_>>(),        32,        "the size of this structure should not changed unexpectedly"    )}