message: expose mask function
diff: @@ -368,7 +368,7 @@ where
  }
  /// Turns a non-hiding polynomial commitment into a hidding polynomial commitment. Transforms each given `<a, G>` into `(<a, G> + wH, w)` with a random `w` per commitment.
  - fn mask(
  + pub fn mask(
  &self,
  c: PolyComm<G>,
  rng: &mut (impl RngCore + CryptoRng),
  