}


  public void testKeySet_populated() {
    for (LoadingCache<Object, Object> cache : caches()) {
      Set<Object> keys = cache.asMap().keySet();
      List<Entry<Object, Object>> warmed = warmUp(cache);

      Set<Object> expected = new HashMap<>(cache.asMap()).keySet();
      assertThat(keys).containsExactlyElementsIn(expected);
      assertThat(keys.toArray()).asList().containsExactlyElementsIn(expected);

  @LazyInit @RetainedWith private transient @Nullable ImmutableSet<K> keySet;

  /**
   * Returns an immutable set of the keys in this map, in the same order that they appear in {@link
   * #entrySet}.
   */
  @Override
  public ImmutableSet<K> keySet() {
    ImmutableSet<K> result = keySet;
    return (result == null) ? keySet = createKeySet() : result;
  }

  /*

    assertMultimapRemainsUnmodified(multimap, originalEntries);

    // Test #keySet()
    assertSetIsUnmodifiable(multimap.keySet(), sampleKey);
    assertMultimapRemainsUnmodified(multimap, originalEntries);

    // Test #get()
    if (!multimap.isEmpty()) {
      K key = multimap.keySet().iterator().next();
      assertCollectionIsUnmodifiable(multimap.get(key), sampleValue);

    }
  }

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

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

    // 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();

    }
  }

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

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

    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 =

  @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);
  }