Derive `maxAge` from function return value?

[gregory-j-baker]

Is it possible to set a cache's maxAge according to the value that is returned by the memoized function?

I am fetching an OAuth access token which has an expires_in value, and I would like to cache the token for approximately as long as it is valid. The problem is that the value of expires_in is set by the remote auth server and is unknown until I actually fetch the token.