code: public Retryer<R> timeout(long duration, TimeUnit timeUnit, ExecutorService executor) {
          return timeout(null == executor
                  ? new SimpleTimeLimiter() : new SimpleTimeLimiter(executor), duration, timeUnit);
      }
docs: Timing out after the specified time limit with {@link ExecutorService}
  
  @param duration
  @param timeUnit
  @param executor
  @return