Replace any `unwrap` calls in documentation examples by `?` per the guidance here: https://rust-lang.github.io/api-guidelines/documentation.html#examples-use--not-try-not-unwrap-c-question-mark
Replace any `unwrap` calls in documentation examples by `?` per the guidance here: https://rust-lang.github.io/api-guidelines/documentation.html#examples-use--not-try-not-unwrap-c-question-mark