private ImmutableEnumMap(EnumMap<K, V> delegate) {
    this.delegate = delegate;
    checkArgument(!delegate.isEmpty());
  }

  @Override
  UnmodifiableIterator<K> keyIterator() {
    return Iterators.unmodifiableIterator(delegate.keySet().iterator());
  }

  @Override
  public int size() {
    return delegate.size();
  }

  @Override

   * overrides it.
   */
  abstract ImmutableSet<K> createKeySet();

  UnmodifiableIterator<K> keyIterator() {
    final UnmodifiableIterator<Entry<K, V>> entryIterator = entrySet().iterator();
    return new UnmodifiableIterator<K>() {
      @Override
      public boolean hasNext() {
        return entryIterator.hasNext();
      }

      @Override

/**
 * Tests for {@link UnmodifiableIterator}.
 *
 * @author Jared Levy
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public class UnmodifiableIteratorTest extends TestCase {

  @SuppressWarnings("DoNotCall")
  public void testRemove() {
    final String[] array = {"a", "b", "c"};

    Iterator<String> iterator =
        new UnmodifiableIterator<String>() {
          int i;

  }

  ImmutableSet<K> createKeySet() {
    return new ImmutableMapKeySet<K, V>(this);
  }

  UnmodifiableIterator<K> keyIterator() {
    final UnmodifiableIterator<Entry<K, V>> entryIterator = entrySet().iterator();
    return new UnmodifiableIterator<K>() {
      @Override
      public boolean hasNext() {
        return entryIterator.hasNext();
      }

      @Override

    Object writeReplace() {
      return super.writeReplace();
    }

    private static final long serialVersionUID = 0;
  }

  @Override
  UnmodifiableIterator<Entry<K, V>> entryIterator() {
    return new UnmodifiableIterator<Entry<K, V>>() {
      final Iterator<? extends Entry<K, ? extends ImmutableCollection<V>>> asMapItr =
          map.entrySet().iterator();
      @CheckForNull K currentKey = null;

  ForwardingImmutableSet(Set<E> delegate) {
    // TODO(cpovirk): are we over-wrapping?
    this.delegate = Collections.unmodifiableSet(delegate);
  }

  @Override
  public UnmodifiableIterator<E> iterator() {
    return Iterators.unmodifiableIterator(delegate.iterator());
  }

  @Override
  public boolean contains(@Nullable Object object) {
    return object != null && delegate.contains(object);
  }

  @Override

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

        @Override
        public Iterator<K> iterator() {
          return Iterators.unmodifiableIterator(delegate.keySet().iterator());
        }

        @Override
        public boolean removeAll(Collection<?> c) {
          return delegate.keySet().removeAll(c);
        }

        @Override

    Object writeReplace() {
      return super.writeReplace();
    }

    private static final long serialVersionUID = 0;
  }

  @Override
  UnmodifiableIterator<Entry<K, V>> entryIterator() {
    return new UnmodifiableIterator<Entry<K, V>>() {
      final Iterator<? extends Entry<K, ? extends ImmutableCollection<V>>> asMapItr =
          map.entrySet().iterator();
      @CheckForNull K currentKey = null;

  final transient Collection<E> delegate;

  ForwardingImmutableCollection(Collection<E> delegate) {
    this.delegate = delegate;
  }

  @Override
  public UnmodifiableIterator<E> iterator() {
    return Iterators.unmodifiableIterator(delegate.iterator());
  }

  @Override
  public boolean contains(@Nullable Object object) {
    return object != null && delegate.contains(object);
  }

  @Override

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

        @Override
        public Iterator<K> iterator() {
          return Iterators.unmodifiableIterator(delegate.keySet().iterator());
        }

        @Override
        public boolean removeAll(Collection<?> c) {
          return delegate.keySet().removeAll(c);
        }

        @Override