use rand::distributions::{Distribution, Standard};
use rand::prelude::*;
use rand::rngs::StdRng;
pub fn vec<T>(size: usize, start: usize) -> Option<Vec<T>>
where
Standard: Distribution<T>,
{
if size > start + 2 {
let mut rng = StdRng::from_entropy();
Some((0..size).map(|_| rng.gen()).collect())
} else {
None
}
}