*
   * @return the required wait time, never negative
   */
  final long reserveAndGetWaitLength(int permits, long nowMicros) {
    long momentAvailable = reserveEarliestAvailable(permits, nowMicros);
    return max(momentAvailable - nowMicros, 0);
  }

  /**
   * Returns the earliest time that permits are available (with one caveat).
   *

    return SECONDS.toMicros(1L) / stableIntervalMicros;
  }

  @Override
  final long queryEarliestAvailable(long nowMicros) {
    return nextFreeTicketMicros;
  }

  @Override
  final long reserveEarliestAvailable(int requiredPermits, long nowMicros) {
    resync(nowMicros);
    long returnValue = nextFreeTicketMicros;
    double storedPermitsToSpend = min(requiredPermits, this.storedPermits);