public static <E> ImmutableSet<E> of() {
    return (ImmutableSet<E>) RegularImmutableSet.EMPTY;
  }

  /**
   * Returns an immutable set containing {@code element}. Preferred over {@link
   * Collections#singleton} for code consistency, {@code null} rejection, and because the return
   * type conveys the immutability guarantee.
   */
  public static <E> ImmutableSet<E> of(E element) {

  public static <E> ImmutableSet<E> of() {
    return (ImmutableSet<E>) RegularImmutableSet.EMPTY;
  }

  /**
   * Returns an immutable set containing {@code element}. Preferred over {@link
   * Collections#singleton} for code consistency, {@code null} rejection, and because the return
   * type conveys the immutability guarantee.
   */
  public static <E> ImmutableSet<E> of(E element) {

   * parameters used to build this multimap.
   */
  @Override
  public ImmutableSet<V> get(K key) {
    // This cast is safe as its type is known in constructor.
    ImmutableSet<V> set = (ImmutableSet<V>) map.get(key);
    return MoreObjects.firstNonNull(set, emptySet);
  }

    return new SpliteratorTester<>(
        ImmutableSet.of(
            () -> new GeneralSpliteratorOfObject<>(spliteratorSupplier.get()),
            () -> new GeneralSpliteratorOfPrimitive<>(spliteratorSupplier.get(), c -> c::accept)));
  }

  private final ImmutableSet<Supplier<GeneralSpliterator<E>>> spliteratorSuppliers;

  private SpliteratorTester(ImmutableSet<Supplier<GeneralSpliterator<E>>> spliteratorSuppliers) {

  }

  abstract ImmutableSet<Entry<K, V>> createEntrySet();

  @LazyInit @RetainedWith @CheckForNull private transient 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;

  @Override
  public abstract ImmutableSet<E> elementSet();

  @LazyInit @CheckForNull private transient ImmutableSet<Entry<E>> entrySet;

  @Override
  public ImmutableSet<Entry<E>> entrySet() {
    ImmutableSet<Entry<E>> es = entrySet;
    return (es == null) ? (entrySet = createEntrySet()) : es;
  }

  private ImmutableSet<Entry<E>> createEntrySet() {

          return alternatingKeysAndValues[keyIndex ^ 1];
        }
      }
    }
  }

  @Override
  ImmutableSet<Entry<K, V>> createEntrySet() {
    return new EntrySet<>(this, alternatingKeysAndValues, 0, size);
  }

  static class EntrySet<K, V> extends ImmutableSet<Entry<K, V>> {
    private final transient ImmutableMap<K, V> map;
    private final transient @Nullable Object[] alternatingKeysAndValues;

  @Beta // TODO: b/288085449 - Remove.
  public static <E> Collector<E, ?, ImmutableSet<E>> toImmutableSet() {
    throw new UnsupportedOperationException();
  }

  /**
   * Not supported. Use {@link #naturalOrder}, which offers better type-safety, instead. This method
   * exists only to hide {@link ImmutableSet#builder} from consumers of {@code ImmutableSortedSet}.
   *

      }
    }
  }

  ImmutableTable() {}

  @Override
  public ImmutableSet<Cell<R, C, V>> cellSet() {
    return (ImmutableSet<Cell<R, C, V>>) super.cellSet();
  }

  @Override
  abstract ImmutableSet<Cell<R, C, V>> createCellSet();

  @Override
  final UnmodifiableIterator<Cell<R, C, V>> cellIterator() {

    LinkedHashSet<E> set = Sets.newLinkedHashSet();
    set.add(freshElement);
    return set;
  }

  @Generates
  static <E> ImmutableSet<E> generateImmutableSet(E freshElement) {
    return ImmutableSet.of(freshElement);
  }

  @Generates
  static <E extends Comparable<? super E>> SortedSet<E> generateSortedSet(E freshElement) {
    return generateNavigableSet(freshElement);