code: private long getWaitUntilMillis(int retryAfterSeconds) {
      double multiplier = waitTimeNoiseFactor.get().nextDouble();
      multiplier =
          multiplier * (MAX_WAIT_TIME_MULTIPLIER - MIN_WAIT_TIME_MULTIPLIER)
              + MIN_WAIT_TIME_MULTIPLIER;
      double result = SECONDS.toMillis(retryAfterSeconds) * multiplier;
      return (long) result;
    }
docs: Decides the actual wait time in milliseconds, by applying a random multiplier to
  retryAfterSeconds.