for (int i = 0; i < 10; i++) {
      cache.getUnchecked(i);
      ticker.advance(1, MILLISECONDS);
    }
    Set<Integer> keySet = cache.asMap().keySet();
    assertThat(keySet).containsExactly(0, 1, 2, 3, 4, 5, 6, 7, 8, 9);

    // 0 expires
    ticker.advance(1, MILLISECONDS);
    assertThat(keySet).containsExactly(1, 2, 3, 4, 5, 6, 7, 8, 9);

    // reorder
    getAll(cache, asList(0, 1, 2));

    }

    @LazyInit private transient @Nullable Set<K> keySet;

    @Override
    public Set<K> keySet() {
      Set<K> result = keySet;
      return (result == null) ? keySet = createKeySet() : result;
    }

    Set<K> createKeySet() {
      return new KeySet<>(this);
    }

    @LazyInit private transient @Nullable Collection<V> values;

    }

    @LazyInit private transient @Nullable Set<K> keySet;

    @Override
    public Set<K> keySet() {
      Set<K> result = keySet;
      return (result == null) ? keySet = createKeySet() : result;
    }

    Set<K> createKeySet() {
      return new KeySet<>(this);
    }

    @LazyInit private transient @Nullable Collection<V> values;

  }

  public SafeTreeMap(SortedMap<K, ? extends V> map) {
    this(new TreeMap<K, V>(map));
  }

  private SafeTreeMap(NavigableMap<K, V> delegate) {
    this.delegate = checkNotNull(delegate);
    for (K k : keySet()) {
      checkValid(k);
    }
  }

  @Override
  public @Nullable Entry<K, V> ceilingEntry(K key) {
    return delegate.ceilingEntry(checkValid(key));
  }

  @Override

  }

  public SafeTreeMap(SortedMap<K, ? extends V> map) {
    this(new TreeMap<K, V>(map));
  }

  private SafeTreeMap(NavigableMap<K, V> delegate) {
    this.delegate = checkNotNull(delegate);
    for (K k : keySet()) {
      checkValid(k);
    }
  }

  @Override
  public @Nullable Entry<K, V> ceilingEntry(K key) {
    return delegate.ceilingEntry(checkValid(key));
  }

  @Override

    for (Segment<K, V, E, S> segment : segments) {
      segment.clear();
    }
  }

  @LazyInit transient @Nullable Set<K> keySet;

  @Override
  public Set<K> keySet() {
    Set<K> ks = keySet;
    return (ks != null) ? ks : (keySet = new KeySet());
  }

  @LazyInit transient @Nullable Collection<V> values;

  @Override
  public Collection<V> values() {

    for (Segment<K, V, E, S> segment : segments) {
      segment.clear();
    }
  }

  @LazyInit transient @Nullable Set<K> keySet;

  @Override
  public Set<K> keySet() {
    Set<K> ks = keySet;
    return (ks != null) ? ks : (keySet = new KeySet());
  }

  @LazyInit transient @Nullable Collection<V> values;

  @Override
  public Collection<V> values() {

    protected void writeFessConfig(final ZipOutputStream zos, final String id) {
        if (fessConfig instanceof SimpleImpl) {
            final Properties prop = new Properties();
            ((SimpleImpl) fessConfig).keySet().stream().forEach(k -> prop.setProperty(k, fessConfig.get(k)));

            final ZipEntry entry = new ZipEntry(id + "/fess_config.properties");
            try {
                zos.putNextEntry(entry);

    for (Object key : keys) {
      remove(key);
    }
  }

  @LazyInit @RetainedWith @Nullable Set<K> keySet;

  @Override
  public Set<K> keySet() {
    // does not impact recency ordering
    Set<K> ks = keySet;
    return (ks != null) ? ks : (keySet = new KeySet());
  }

  @LazyInit @RetainedWith @Nullable Collection<V> values;

  @Override
  public Collection<V> values() {

    for (Object key : keys) {
      remove(key);
    }
  }

  @LazyInit @RetainedWith @Nullable Set<K> keySet;

  @Override
  public Set<K> keySet() {
    // does not impact recency ordering
    Set<K> ks = keySet;
    return (ks != null) ? ks : (keySet = new KeySet());
  }

  @LazyInit @RetainedWith @Nullable Collection<V> values;

  @Override
  public Collection<V> values() {