* delegation to save code size.
 *
 * @author Hayward Chan
 */
final class ForwardingImmutableCollection<E> extends ImmutableCollection<E> {

  final transient Collection<E> delegate;

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

  @Override
  public UnmodifiableIterator<E> iterator() {

   */
  int internalArrayEnd() {
    throw new UnsupportedOperationException();
  }

  static <E> ImmutableCollection<E> unsafeDelegate(Collection<E> delegate) {
    return new ForwardingImmutableCollection<E>(delegate);
  }

  boolean isPartialView() {
    return false;
  }

  /** GWT emulated version of {@link ImmutableCollection.Builder}. */
  public abstract static class Builder<E> {