return MILLISECONDS;
    }
    if (MICROSECONDS.convert(nanos, NANOSECONDS) > 0) {
      return MICROSECONDS;
    }
    return NANOSECONDS;
  }

  private static String abbreviate(TimeUnit unit) {
    switch (unit) {
      case NANOSECONDS:
        return "ns";
      case MICROSECONDS:
        return "\u03bcs"; // μs
      case MILLISECONDS:
        return "ms";

  }

  public void testElapsed_micros() {
    stopwatch.start();
    ticker.advance(999);
    assertEquals(0, stopwatch.elapsed(MICROSECONDS));
    ticker.advance(1);
    assertEquals(1, stopwatch.elapsed(MICROSECONDS));
  }

  public void testElapsed_millis() {
    stopwatch.start();
    ticker.advance(999999);
    assertEquals(0, stopwatch.elapsed(MILLISECONDS));

  }

  /**
   * Reserves the given number of permits from this {@code RateLimiter} for future use, returning
   * the number of microseconds until the reservation can be consumed.
   *
   * @return time in microseconds to wait until the resource can be acquired, never negative
   */
  final long reserve(int permits) {
    checkPermits(permits);
    synchronized (mutex()) {

  }

  public void testElapsed_micros() {
    stopwatch.start();
    ticker.advance(999);
    assertEquals(0, stopwatch.elapsed(MICROSECONDS));
    ticker.advance(1);
    assertEquals(1, stopwatch.elapsed(MICROSECONDS));
  }

  public void testElapsed_millis() {
    stopwatch.start();
    ticker.advance(999999);
    assertEquals(0, stopwatch.elapsed(MILLISECONDS));

 * for information on the behaviour of the algorithm.
 *
 * <p>On Intel Core2 2.66, on 1000 bytes, fingerprint2011 takes 0.9 microseconds compared to
 * fingerprint at 4.0 microseconds and md5 at 4.5 microseconds.
 *
 * <p>Note to maintainers: This implementation relies on signed arithmetic being bit-wise equivalent
 * to unsigned arithmetic in all cases except:
 *
 * <ul>

  }

  /**
   * Reserves the given number of permits from this {@code RateLimiter} for future use, returning
   * the number of microseconds until the reservation can be consumed.
   *
   * @return time in microseconds to wait until the resource can be acquired, never negative
   */
  final long reserve(int permits) {
    checkPermits(permits);
    synchronized (mutex()) {

#### The time to answer helps the attackers

  }

  public void testTryAcquire_overflow() {
    RateLimiter limiter = RateLimiter.create(5.0, stopwatch);
    assertTrue(limiter.tryAcquire(0, MICROSECONDS));
    stopwatch.sleepMillis(100);
    assertTrue(limiter.tryAcquire(Long.MAX_VALUE, MICROSECONDS));
  }

  public void testTryAcquire_negative() {
    RateLimiter limiter = RateLimiter.create(5.0, stopwatch);
    assertTrue(limiter.tryAcquire(5, 0, SECONDS));

  }

  public void testTryAcquire_overflow() {
    RateLimiter limiter = RateLimiter.create(5.0, stopwatch);
    assertTrue(limiter.tryAcquire(0, MICROSECONDS));
    stopwatch.sleepMillis(100);
    assertTrue(limiter.tryAcquire(Long.MAX_VALUE, MICROSECONDS));
  }

  public void testTryAcquire_negative() {
    RateLimiter limiter = RateLimiter.create(5.0, stopwatch);
    assertTrue(limiter.tryAcquire(5, 0, SECONDS));

	labels = append(labels, "api", "")
	lastIdx := len(labels) - 1
	for apiName, latency := range disk.Metrics.LastMinute {
		labels[lastIdx] = "storage." + apiName
		m.Set(driveAPILatencyMicros, float64(latency.Avg().Microseconds()),
			labels...)
	}
}

func (m *MetricValues) setDriveIOStatMetrics(ioStats driveIOStatMetrics, labels []string) {
	m.Set(driveReadsPerSec, ioStats.readsPerSec, labels...)