Does this lib store the access tokens in some kind of cache or retrieve it each request?

[TowhidKashem]

Normally when I need to get a service level access token from Google I need to make a request to google to swap the JWT with an access token. I usually store this in something like workers KV and since the token expires every hour I only need to hit this endpoint once every hour and the rest of the time I use the one in the KV cache.

This lib doesn't accept a way to pass in a KV binding which makes me wonder, is it making the external request for every single request by every user?