* @throws IllegalStateException if {@link #expireAfterAccess} was already set
   */
  @SuppressWarnings("GoodTime") // should accept a Duration
  @CanIgnoreReturnValue
  public CacheBuilder<K, V> expireAfterAccess(long duration, TimeUnit unit) {
    checkState(
        expireAfterAccessNanos == UNSET_INT,
        "expireAfterAccess was already set to %s ns",
        expireAfterAccessNanos);

        ConcurrentMapTestSuiteBuilder.using(
                new TestStringCacheGenerator(
                    createCacheBuilder()
                        .expireAfterAccess(1, SECONDS)
                        .ticker(new SerializableTicker())))
            .named("LocalCache with expireAfterAccess") // SerializableTicker never advances
            .withFeatures(
                CollectionSize.ANY,
                MapFeature.GENERAL_PURPOSE,

    }
    if (expireAfterWrite != null) {
      builder.expireAfterWrite(expireAfterWrite.duration, expireAfterWrite.unit);
    }
    if (expireAfterAccess != null) {
      builder.expireAfterAccess(expireAfterAccess.duration, expireAfterAccess.unit);
    }
    if (refresh != null) {
      builder.refreshAfterWrite(refresh.duration, refresh.unit);
    }
    if (keyStrength != null) {

  private boolean isExpired(Timestamped<V> stamped) {
    if ((expireAfterAccess == UNSET_INT) && (expireAfterWrite == UNSET_INT)) {
      return false;
    }

    boolean expireWrite = stamped.getWriteTimestamp() + expireAfterWrite <= currentTimeNanos();
    boolean expireAccess = stamped.getAccessTimestamp() + expireAfterAccess <= currentTimeNanos();

    if (expireAfterAccess == UNSET_INT) {
      return expireWrite;
    }

    CacheBuilder.newBuilder().expireAfterAccess(1, NANOSECONDS).build(identityLoader());
    // well, it didn't blow up.
  }

  public void testTimeToIdle_setTwice() {
    CacheBuilder<Object, Object> builder =
        CacheBuilder.newBuilder().expireAfterAccess(3600, SECONDS);
    assertThrows(IllegalStateException.class, () -> builder.expireAfterAccess(3600, SECONDS));
  }

  @GwtIncompatible // Duration

    CacheBuilder.newBuilder().expireAfterAccess(1, NANOSECONDS).build(identityLoader());
    // well, it didn't blow up.
  }

  public void testTimeToIdle_setTwice() {
    CacheBuilder<Object, Object> builder =
        CacheBuilder.newBuilder().expireAfterAccess(3600, SECONDS);
    assertThrows(IllegalStateException.class, () -> builder.expireAfterAccess(3600, SECONDS));
  }

  @GwtIncompatible // Duration

    WatchedCreatorLoader loader = new WatchedCreatorLoader();
    LoadingCache<String, Integer> cache =
        CacheBuilder.newBuilder()
            .expireAfterAccess(EXPIRING_TIME, MILLISECONDS)
            .removalListener(removalListener)
            .ticker(ticker)
            .build(loader);
    checkExpiration(cache, loader, ticker, removalListener);
  }

    checkEmpty(cache);
  }

  public void testGet_expireAfterAccess() {
    Object computed = new Object();
    LoadingCache<Object, Object> cache =
        CacheBuilder.newBuilder()
            .expireAfterAccess(0, SECONDS)
            .removalListener(listener)
            .build(constantLoader(computed));

    Object key = new Object();
    assertSame(computed, cache.getUnchecked(key));

    checkEmpty(cache);
  }

  public void testGet_expireAfterAccess() {
    Object computed = new Object();
    LoadingCache<Object, Object> cache =
        CacheBuilder.newBuilder()
            .expireAfterAccess(0, SECONDS)
            .removalListener(listener)
            .build(constantLoader(computed));

    Object key = new Object();
    assertSame(computed, cache.getUnchecked(key));

    assertEquals(Integer.valueOf(6), cache.apply(7));
  }

  public void testExpireAfterAccess() {
    Cache<Integer, Integer> cache =
        CacheBuilder.newBuilder().expireAfterAccess(1000, MILLISECONDS).ticker(fakeTicker).build();

    cache.put(0, 10);
    cache.put(2, 30);

    fakeTicker.advance(999, MILLISECONDS);
    assertEquals(Integer.valueOf(30), cache.getIfPresent(2));