SearchOptions.facetFilters does not take string[][] as type

i’m trying to use multiple facet filters as according to the docs here: Filters and facet filters | Algolia. according to this guide i can make a query like

index.search('', { facetFilters: [["author:Stephen King", "genre:Horror"], "publisher:Penguin"] }); .

I’m using typescript, and so i’m expecting facetFilters to be able to receive a type like (string | string[])[]. However, in the client-search Typescript library, facet filters is

readonly facetFilters?: string | readonly string[] | ReadonlyArray<readonly string[]>;

so, is the library not up to date with the docs? or am i looking at the wrong function?