message: Implement `Clone` for Bls12.
diff: @@ -21,7 +21,7 @@ use super::{Engine, CurveAffine, Field, BitIterator};
  const BLS_X: u64 = 0xd201000000010000;
  const BLS_X_IS_NEGATIVE: bool = true;
  -#[derive(Debug)]
  +#[derive(Clone, Debug)]
  pub struct Bls12;
  impl Engine for Bls12 {
  