in src/hashwires.rs [393:402]
fn compute_plr_roots<D: Hash>(
plr_roots: &[GenericArray<u8, PlrPaddingSize>],
salts: &[GenericArray<u8, MdpSaltSize>],
) -> Vec<[u8; 32]> {
plr_roots
.iter()
.enumerate()
.map(|(i, v)| salted_hash::<D>(&salts[i], v))
.collect()
}