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

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

  abstract Set<K> createKeySet();

  @LazyInit private transient @Nullable Multiset<K> keys;

  @Override
  public Multiset<K> keys() {
    Multiset<K> result = keys;

    return (SortedMap<K, Collection<V>>) super.backingMap();
  }

  @Override
  public SortedSet<K> keySet() {
    return (SortedSet<K>) super.keySet();
  }

  @Override
  Set<K> createKeySet() {
    return createMaybeNavigableKeySet();
  }

  }

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

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

  abstract Set<K> createKeySet();

  @LazyInit private transient @Nullable Multiset<K> keys;

  @Override
  public Multiset<K> keys() {
    Multiset<K> result = keys;

    return (SortedMap<K, Collection<V>>) super.backingMap();
  }

  @Override
  public SortedSet<K> keySet() {
    return (SortedSet<K>) super.keySet();
  }

  @Override
  Set<K> createKeySet() {
    return createMaybeNavigableKeySet();
  }

  }

  @Override
  ImmutableSet<Entry<K, V>> createEntrySet() {
    return new ImmutableMapEntrySet.RegularEntrySet<>(this, entries);
  }

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

  @Override
  boolean isPartialView() {
    return false;
  }

  // redeclare to help optimizers with b/310253115

    throw new AssertionError("should never be called");
  }

  @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();

  }

  @Override
  ImmutableSet<Entry<K, V>> createEntrySet() {
    return new RegularImmutableMap.EntrySet<K, V>(this, alternatingKeysAndValues, keyOffset, size);
  }

  @Override
  ImmutableSet<K> createKeySet() {
    @SuppressWarnings("unchecked")
    ImmutableList<K> keyList =
        (ImmutableList<K>)
            new RegularImmutableMap.KeysOrValuesAsList(alternatingKeysAndValues, keyOffset, size);

  ImmutableSet<Entry<K, V>> createEntrySet() {
    return isEmpty()
        ? ImmutableSet.of()
        : new ImmutableMapEntrySet.RegularEntrySet<K, V>(this, entries);
  }

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

  @Override
  public void forEach(BiConsumer<? super K, ? super V> action) {
    checkNotNull(action);
    for (Entry<K, V> entry : entries) {

    throw new AssertionError("should never be called");
  }

  @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();

  @Override
  public void forEach(BiConsumer<? super K, ? super V> action) {
    checkNotNull(action);
    entries.forEach(e -> action.accept(e.getKey(), e.getValue()));
  }

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

  @Override
  ImmutableCollection<V> createValues() {
    return new ImmutableMapValues<>(this);
  }

  @Override