.expireAfterWrite(EXPIRING_TIME, MILLISECONDS)
            .removalListener(removalListener)
            .ticker(ticker)
            .build(loader);
    checkExpiration(cache, loader, ticker, removalListener);
  }

  public void testExpiration_expireAfterAccess() {
    FakeTicker ticker = new FakeTicker();
    CountingRemovalListener<String, Integer> removalListener = countingRemovalListener();

  }

  public void testElapsed_notRunning() {
    ticker.advance(1);
    stopwatch.start();
    ticker.advance(4);
    stopwatch.stop();
    ticker.advance(9);
    assertEquals(4, stopwatch.elapsed(NANOSECONDS));
  }

  public void testElapsed_multipleSegments() {
    stopwatch.start();
    ticker.advance(9);
    stopwatch.stop();

    ticker.advance(16);

    stopwatch.start();

import com.google.common.annotations.J2ktIncompatible;
import com.google.common.base.Ticker;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.time.Duration;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicLong;

/**
 * A Ticker whose value can be advanced programmatically in test.
 *
 * <p>The ticker can be configured so that the time is incremented whenever {@link #read} is called:

  private static class Timestamped<V> {
    private final V value;
    private final Ticker ticker;
    private long writeTimestamp;
    private long accessTimestamp;

    public Timestamped(V value, Ticker ticker) {
      this.value = checkNotNull(value);
      this.ticker = checkNotNull(ticker);
      this.writeTimestamp = ticker.read();
      this.accessTimestamp = this.writeTimestamp;
    }

            return Futures.immediateFuture(two);
          }
        };

    LoadingCache<Object, Object> cache =
        CacheBuilder.newBuilder()
            .recordStats()
            .ticker(ticker)
            .refreshAfterWrite(1, MILLISECONDS)
            .build(loader);
    Object key = new Object();
    CacheStats stats = cache.stats();
    assertEquals(0, stats.missCount());

      @Override
      public String toString() {
        return string;
      }
    };
  }

  @Generates
  Ticker generateTicker() {
    return new Ticker() {
      @Override
      public long read() {
        return 0;
      }

      final String string = paramString(Ticker.class, generateInt());

      @Override
      public String toString() {
        return string;
      }
    };

import com.google.common.base.Equivalence;
import com.google.common.base.Joiner;
import com.google.common.base.Predicate;
import com.google.common.base.Splitter;
import com.google.common.base.Stopwatch;
import com.google.common.base.Ticker;
import com.google.common.collect.BiMap;
import com.google.common.collect.ClassToInstanceMap;
import com.google.common.collect.ImmutableBiMap;
import com.google.common.collect.ImmutableClassToInstanceMap;

@ElementTypesAreNonnullByDefault
public abstract class Ticker {
  /** Constructor for use by subclasses. */
  protected Ticker() {}

  /** Returns the number of nanoseconds elapsed since this ticker's fixed point of reference. */
  public abstract long read();

  /**
   * A ticker that reads the current time using {@link System#nanoTime}.
   *
   * @since 10.0
   */
  public static Ticker systemTicker() {
    return SYSTEM_TICKER;
  }

 * will be constant across algorithms).
 *
 * @author Pete Gillin
 * @since 20.0
 */
enum QuantilesAlgorithm {

  /**
   * Sorts the dataset, and picks values from it. When computing multiple quantiles, we sort once
   * and pick multiple values.
   */
  SORTING {

    @Override
    double singleQuantile(int index, int scale, double[] dataset) {

 * will be constant across algorithms).
 *
 * @author Pete Gillin
 * @since 20.0
 */
enum QuantilesAlgorithm {

  /**
   * Sorts the dataset, and picks values from it. When computing multiple quantiles, we sort once
   * and pick multiple values.
   */
  SORTING {

    @Override
    double singleQuantile(int index, int scale, double[] dataset) {