AutoValue: Allow using a Comparator for fluent building

Hello!
I am using AutoValue `1.11.0` (and Java 21) and I'm trying to use an `ImmutableSortedSet` in an `AutoValue`, and that has an `AutoValue.Builder`. I'd like to pass in a `Comparator` so that I can decide how the set gets ordered.

I'm also really fond of the fluent builder style, and I've been using what is described [here in the builders how-to](https://github.com/google/auto/blob/main/value/userguide/builders-howto.md#add).

However, that breaks when I'm trying to use a `Comparator`. The generated code (rightly) does not let me call `ImmutableSortedSet.Builder elementsBuilder(Comparator comparator)` more than once. The pattern given in the how-to, however, would have me do that. I've tried having it also generate a `ImmutableSortedSet.Builder elementsBuilder()`, but if both are present, it only generates the no-arg method.

I can see some workarounds, and I'm probably going to try them in the meantime.

- Caching the `elementsBuilder` in the abstract class
- I'm the one writing the `Element` class in this case, so I could implement `Comparable` (could get messy with inheritances though)
- Having my "fluent" accumulator accept some `Consumer>` argument?
- "Break the chain" and just let whoever is using the builder have to hold their own references

I can see trying to generate both the one-arg and the no-arg methods getting messy because it wouldn't be possible to really enforce which gets called first/which to initialize the sub-builder with. I'm not sure about other possible generated solutions.

Is there an official recommendation for how to do this, or documentation that I missed reading? I've read through [984](https://github.com/google/auto/issues/984) and friends, but I haven't found anything mixing the one-arg constructor and the fluent builder.

Thank you for your help!