// Tests that serializing a map, its keySet, and values only writes the underlying data once.

    Object[] entries = new Object[2000];
    for (int i = 0; i < entries.length; i++) {
      entries[i] = i;
    }

    ImmutableMap<Integer, Integer> map = RegularImmutableMap.create(entries.length / 2, entries);
    Set<Integer> keySet = map.keySet();
    Collection<Integer> values = map.values();

    cache.put(20, 22);
    cache.put(5, 10);

    fakeTicker.advance(501, MILLISECONDS);

    assertTrue(cache.asMap().keySet().contains(20));
    assertTrue(cache.asMap().keySet().contains(5));
    assertFalse(cache.asMap().keySet().contains(10));
  }

  public void testAsMapEntrySet() {
    Cache<Integer, Integer> cache =

    cache.getUnchecked(one);
    Map<Object, Object> newMap = ImmutableMap.of(one, one);
    assertEquals(newMap, map);
    assertEquals(newMap.entrySet(), map.entrySet());
    assertEquals(newMap.keySet(), map.keySet());
    Set<Object> expectedValues = ImmutableSet.of(one);
    Set<Object> actualValues = ImmutableSet.copyOf(map.values());
    assertEquals(expectedValues, actualValues);
  }

  }

  @Override
  Map<K, Collection<V>> createAsMap() {
    return new AsMap();
  }

  @Override
  Set<K> createKeySet() {
    return asMap().keySet();
  }

  boolean removeEntriesIf(Predicate<? super Entry<K, Collection<V>>> predicate) {
    Iterator<Entry<K, Collection<V>>> entryIterator = unfiltered.asMap().entrySet().iterator();
    boolean changed = false;

  @Override
  public boolean isEmpty() {
    return delegate().isEmpty();
  }

  @Override
  public Multiset<K> keys() {
    return delegate().keys();
  }

  @Override
  public Set<K> keySet() {
    return delegate().keySet();
  }

  @CanIgnoreReturnValue
  @Override
  public boolean put(@ParametricNullness K key, @ParametricNullness V value) {
    return delegate().put(key, value);
  }

    assertTrue(multimap.keySet() instanceof SortedSet);
    assertTrue(multimap.asMap() instanceof SortedMap);
  }

  public void testTreeKeys_gwtCompatible() {
    ListMultimap<String, Integer> multimap =
        rawtypeToWildcard(MultimapBuilder.treeKeys()).arrayListValues().<String, Integer>build();
    assertTrue(multimap.keySet() instanceof SortedSet);

  @Override
  public boolean isEmpty() {
    return delegate().isEmpty();
  }

  @Override
  public Multiset<K> keys() {
    return delegate().keys();
  }

  @Override
  public Set<K> keySet() {
    return delegate().keySet();
  }

  @CanIgnoreReturnValue
  @Override
  public boolean put(@ParametricNullness K key, @ParametricNullness V value) {
    return delegate().put(key, value);
  }

  }

  @Override
  ImmutableSet<K> createKeySet() {
    return new KeySet<>(this);
  }

  private static final class KeySet<K> extends IndexedImmutableSet<K> {
    private final RegularImmutableMap<K, ?> map;

    KeySet(RegularImmutableMap<K, ?> map) {
      this.map = map;
    }

    @Override
    K get(int index) {

      String value2 = key2.toString();
      assertSame(value1, cache.getUnchecked(key1));
      assertSame(value2, cache.getUnchecked(key2));
      assertEquals(ImmutableSet.of(key1, key2), cache.asMap().keySet());
      assertThat(cache.asMap().values()).containsExactly(value1, value2);
      assertEquals(
          ImmutableSet.of(immutableEntry(key1, value1), immutableEntry(key2, value2)),
          cache.asMap().entrySet());

    }
  }

  public void testAsMapGetImplementsList() {
    for (K key : multimap().keySet()) {
      assertTrue(multimap().asMap().get(key) instanceof List);
    }
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testAsMapRemoveImplementsList() {
    List<K> keys = new ArrayList<>(multimap().keySet());
    for (K key : keys) {
      resetCollection();