*  New: `EventListener.retryDecision()` is called each time a request fails with an `IOException`.
    It notifies your listener if OkHttp will retry.

 *  New: `EventListener.followUpDecision()` is called each time a response is received. It notifies
    your listener if OkHttp has decided to make a follow-up request. Some common follow-ups are
    authentication challenges and redirects.