#[cfg(test)]
mod checker {
    use day66::*;

    fn check() {
        assert!(isbn_validator(isbn_generator().trim()).unwrap());
    }

    #[test]
    fn gen1() {
        check();
    }

    #[test]
    fn gen10() {
        for _ in 0..10 {
            check();
        }
    }

    #[test]
    fn gen100() {
        for _ in 0..100 {
            check();
        }
    }
}