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));

#### The time to answer helps the attackers { #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...)

) : Lockable {
  private var nextQueueName = 10000
  private var coordinatorWaiting = false
  private var coordinatorWakeUpAt = 0L

  /**
   * When we need a new thread to run tasks, we call [Backend.execute]. A few microseconds later we
   * expect a newly-started thread to call [Runnable.run]. We shouldn't request new threads until
   * the already-requested ones are in service, otherwise we might create more threads than we need.
   *

 * iterations, to properly test the cache benefits within each measurement period.
 */
@BenchmarkMode(Mode.AverageTime)
@OutputTimeUnit(TimeUnit.MICROSECONDS)
@Warmup(iterations = 3, time = 1)
@Measurement(iterations = 5, time = 10)
@Fork(1)
@State(Scope.Benchmark)
public class CompositeBeanHelperPerformanceTest {

    private ConverterLookup converterLookup;

Instead of that, by being an "asynchronous" system, once finished, the task can wait in line a little bit (some microseconds) for the computer / program to finish whatever it went to do, and then come back to take the results and continue working with them.

   *
   * <p>This always holds: {@code 0 <= permitsToTake <= storedPermits}
   */
  abstract long storedPermitsToWaitTime(double storedPermits, double permitsToTake);

  /**
   * Returns the number of microseconds during cool down that we have to wait to get a new permit.
   */
  abstract double coolDownIntervalMicros();

  /** Updates {@code storedPermits} and {@code nextFreeTicketMicros} based on the current time. */