in src/serialization.rs [319:324]
fn deserialize_scalar<G: Group, I: Iterator<Item = u8>>(input: &mut I) -> Result<G::Scalar> {
let input = input.by_ref().take(G::ScalarLen::USIZE);
GenericArray::<_, G::ScalarLen>::from_exact_iter(input)
.ok_or(Error::Deserialization)
.and_then(|bytes| G::deserialize_scalar(&bytes))
}