pub fn limbs_from_vec<E: From<F>, N: ArrayLength, F: Field>(limbs: Vec<F>) -> Limbs<E, N> {
    debug_assert_eq!(limbs.len(), N::USIZE);
    let mut result = GenericArray::<E, N>::generate(|_i| F::zero().into());
    for (i, limb) in limbs.into_iter().enumerate() {
        result[i] = limb.into();
    }
    Limbs(result)
}
Convert a vec of F limbs to a Limbs of N length.
crates/curves/src/params.rs