pub mod summary {    use std::borrow::Cow;     use git::bstr::ByteSlice;    use git_repository as git;     #[test]    fn no_newline_yields_the_message_itself() {        let input = b"hello world".as_bstr();        assert_eq!(git::commit::summary(input), Cow::Borrowed(input));    }     #[test]    fn trailing_newlines_and_whitespace_are_trimmed() {        let input = b"hello world \t\r\n \n".as_bstr();        assert_eq!(git::commit::summary(input), Cow::Borrowed(b"hello world".as_bstr()));    }     #[test]    fn prefixed_newlines_and_whitespace_are_trimmed() {        let input = b" \t\r\n \nhello world".as_bstr();        assert_eq!(git::commit::summary(input), Cow::Borrowed(b"hello world".as_bstr()));    }     #[test]    fn whitespace_up_to_a_newline_is_collapsed_into_a_space() {        let input = b" \t\r\n \nhello\r\nworld \t\r\n \n".as_bstr();        assert_eq!(git::commit::summary(input), Cow::Borrowed(b"hello world".as_bstr()));    }     #[test]    fn whitespace_without_newlines_is_ignored_except_for_leading_and_trailing_whitespace() {        let input = b" \t\r\n \nhello \t \rworld \t\r\n \n".as_bstr();        assert_eq!(            git::commit::summary(input),            Cow::Borrowed(b"hello \t \rworld".as_bstr())        );    }     #[test]    fn lines_separated_by_double_newlines_are_subjects() {        let input = b" \t\r\n \nhello\t \r\nworld \t\r \nfoo\n\nsomething else we ignore".as_bstr();        assert_eq!(git::commit::summary(input), Cow::Borrowed(b"hello world foo".as_bstr()));    }}