I think this change to the signature is a little odd because the parent and include_subtopics parameters are really interconnected. It doesn't make a lot of sense to speicify both, but there is nothing stopping you. Sadly I can't think of a way to improve this.

Maybe default parent to False? and set it if it isn't False. Then kill include_subtopics?

Oh, that makes sense. I was trying to think of something like that and getting caught up because my usual null value, None, was already a thing.