Spun out of #14911, this changes the return type to an immutable value. Turns out all the callers actually wanted a set so instead of List[str] (or StrSequence) we can return FrozenSet[str]). This also should do less work since we cache exactly what we want and do less set(...) of the return value.
Spun out of #14911, this changes the return type to an immutable value. Turns out all the callers actually wanted a set so instead of
List[str](orStrSequence) we can returnFrozenSet[str]). This also should do less work since we cache exactly what we want and do lessset(...)of the return value.