How can I access the author and date in `html-render:render-one-part`?

I'm trying to access the author(s) and date in the render-one-part method in html-render.rkt. I've added extract-date to the list of methods inherited from the render-mixin. extract-authors is already there.

However, calling them within render-one-part produces null values. I see that extract-authors is used in the render-part-content method, but I thought that ends up calling render-one-part with the same document. Apparently not.

Anyone have any suggestions?

I must have fumble-fingered something somewhere, and then unintentionally unfumbled it, because now those accessors are working.