pub fn random_preimages_with_bounded_len(count: u8, len: usize) -> Vec<Vec<u8>> {
    use rand::distributions::Distribution;

    (0..count)
        .map(|_| {
            let len =
                rand::distributions::Uniform::new(0_usize, len).sample(&mut rand::thread_rng());

            (0..len).map(|_| rand::random::<u8>()).collect::<Vec<u8>>()
        })
        .collect()
}
Generate `count` random preimages with bounded length `len`.
patch-testing/sp1-test/src/lib.rs