How do I clear the insights user token?

I can set the user token (Send events with React InstantSearch Hooks | Algolia). But if my user logs out, how do I unset it again?

The method will only accept a string or number. If I set it to the empty string, I get a whole lot of warnings (The `userToken` parameter is invalid. This can lead to wrong analytics. - Format: [a-zA-Z0-9_-]{1,64}).

Am I supposed to set it to zero? Negative 1? Or are the TS types incorrect and it’s supposed to take null? Is there a missing method (I see a way to get and set the token, but nothing to clear)? Or is there no way to unset it and I’m meant to just keep it pointing to the last user?