message: minor refactor Masker::mask
diff: @@ -356,18 +356,19 @@ impl Masker {
  pub fn mask(self, scalar: f64, model: Model) -> (MaskSeed, MaskObject) {
  let (random_int, mut random_ints) = self.random_ints();
  let Self { config, seed } = self;
  + let (config_n, config_1) = (config.vect, config.unit);
  // clamp the scalar
  - let add_shift_scalar = config.unit.add_shift();
  + let add_shift_1 = config_1.add_shift();
  let scalar_ratio = float_to_ratio_bounded(scalar);
  let zero = Ratio::<BigInt>::from_float(0_f64).unwrap();
  - let scalar_clamped = clamp(&scalar_ratio, &zero, &add_shift_scalar);
  + let scalar_clamped = clamp(&scalar_ratio, &zero, &add_shift_1);
  - let exp_shift = config.vect.exp_shift();
  - let add_shift = config.vect.add_shift();
  - let order = config.vect.order();
  - let higher_bound = &add_shift;
  - let lower_bound = -&add_shift;
  + let exp_shift_n = config_n.exp_shift();
  + let add_shift_n = config_n.add_shift();
  + let order_n = config_n.order();
  + let higher_bound = &add_shift_n;
  + let lower_bound = -&add_shift_n;
  // mask the (scaled) weights
  let masked_weights = model
  @@ -377,23 +378,23 @@ impl Masker {
  let scaled = scalar_clamped * &weight;
  let scaled_clamped = clamp(&scaled, &lower_bound, higher_bound);
  // PANIC_SAFE: shifted weight is guaranteed to be non-negative
  - let shifted = ((scaled_clamped + &add_shift) * &exp_shift)
  + let shifted = ((scaled_clamped + &add_shift_n) * &exp_shift_n)
  .to_integer()
  .to_biguint()
  .unwrap();
  - (shifted + rand_int) % &order
  + (shifted + rand_int) % &order_n
  })
  .collect();
  - let masked_model = MaskVect::new_unchecked(config.vect, masked_weights);
  + let masked_model = MaskVect::new_unchecked(config_n, masked_weights);
  // mask the scalar
  // PANIC_SAFE: shifted scalar is guaranteed to be non-negative
  - let shifted = ((scalar_clamped + &add_shift_scalar) * config.unit.exp_shift())
  + let shifted = ((scalar_clamped + &add_shift_1) * config_1.exp_shift())
  .to_integer()
  .to_biguint()
  .unwrap();
  - let masked = (shifted + random_int) % config.unit.order();
  - let masked_scalar = MaskUnit::new_unchecked(config.unit, masked);
  + let masked = (shifted + random_int) % config_1.order();
  + let masked_scalar = MaskUnit::new_unchecked(config_1, masked);
  (seed, MaskObject::new_unchecked(masked_model, masked_scalar))
  }
  