message: Initialize SmallMap::with_capacity(12)
  Summary: Following diff increases threshold to 32, so use current default threshold 12 to prevent regression.
diff: @@ -421,7 +421,7 @@ impl<'v, V: ValueLike<'v>> ParametersSpec<V> {
  fn insert(&mut self, key: Hashed<StringValue<'v>>, val: Value<'v>) -> bool {
  match &mut self.kwargs {
  None => {
  - let mut mp = SmallMap::with_capacity_largest_vec();
  + let mut mp = SmallMap::with_capacity(12);
  mp.insert_hashed_unique_unchecked(key, val);
  self.kwargs = Some(mp);
  false
  