mod decompose {    use std::borrow::Cow;     #[test]    fn precomposed_unicode_is_decomposed() {        let precomposed = "ä";        let actual = gix_utils::str::decompose(precomposed.into());        assert!(matches!(actual, Cow::Owned(_)), "new data is produced");        assert_eq!(actual, "a\u{308}");    }     #[test]    fn already_decomposed_does_not_copy() {        let decomposed = "a\u{308}";        let actual = gix_utils::str::decompose(decomposed.into());        assert!(            matches!(actual, Cow::Borrowed(_)),            "pass-through as nothing needs to be done"        );        assert_eq!(actual, decomposed);    }} mod precompose {    use std::borrow::Cow;     #[test]    fn decomposed_unicode_is_precomposed() {        let decomposed = "a\u{308}";        let actual = gix_utils::str::precompose(decomposed.into());        assert!(matches!(actual, Cow::Owned(_)), "new data is produced");        assert_eq!(actual.chars().collect::<Vec<_>>(), ['ä']);    }     #[test]    fn already_precomposed_does_not_copy() {        let actual = gix_utils::str::precompose("ä".into());        assert!(            matches!(actual, Cow::Borrowed(_)),            "pass-through as nothing needs to be done"        );        assert_eq!(actual.chars().collect::<Vec<_>>(), ['ä']);    }}