*
 * @since 7.0
 * @author Louis Wasserman
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public abstract class UnmodifiableListIterator<E extends @Nullable Object>
    extends UnmodifiableIterator<E> implements ListIterator<E> {
  /** Constructor for use by subclasses. */
  protected UnmodifiableListIterator() {}

  /**
   * Guaranteed to throw an exception and leave the underlying data unmodified.
   *

  }

  ImmutableList<? extends E> delegateList() {
    return delegateList;
  }

  @SuppressWarnings("unchecked") // safe covariant cast!
  @Override
  public UnmodifiableListIterator<E> listIterator(int index) {
    return (UnmodifiableListIterator<E>) delegateList.listIterator(index);
  }

  @GwtIncompatible // not present in emulated superclass
  @Override
  int copyIntoArray(@Nullable Object[] dst, int offset) {

    try {
      iterator.set("c");
      fail();
    } catch (UnsupportedOperationException expected) {
    }
  }

  UnmodifiableListIterator<String> create() {
    final String[] array = {"a", "b", "c"};

    return new UnmodifiableListIterator<String>() {
      int i;

      @Override
      public boolean hasNext() {
        return i < array.length;
      }

      @Override

    try {
      iterator.set("c");
      fail();
    } catch (UnsupportedOperationException expected) {
    }
  }

  UnmodifiableListIterator<String> create() {
    final String[] array = {"a", "b", "c"};

    return new UnmodifiableListIterator<String>() {
      int i;

      @Override
      public boolean hasNext() {
        return i < array.length;
      }

      @Override

 * {@link #set}, or {@link #add}.
 *
 * @author Jared Levy
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
abstract class AbstractIndexedListIterator<E extends @Nullable Object>
    extends UnmodifiableListIterator<E> {
  private final int size;
  private int position;

  /** Returns the element with the specified index. This method is called by {@link #next()}. */
  @ParametricNullness

 * {@link #set}, or {@link #add}.
 *
 * @author Jared Levy
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
abstract class AbstractIndexedListIterator<E extends @Nullable Object>
    extends UnmodifiableListIterator<E> {
  private final int size;
  private int position;

  /** Returns the element with the specified index. This method is called by {@link #next()}. */
  @ParametricNullness

    return unsafeDelegateList(Lists.subListImpl(this, fromIndex, toIndex));
  }

  @Override
  public UnmodifiableListIterator<E> listIterator() {
    return listIterator(0);
  }

  @Override
  public UnmodifiableListIterator<E> listIterator(int index) {
    return new AbstractIndexedListIterator<E>(size(), index) {
      @Override
      protected E get(int index) {

    return listIterator();
  }

  @Override
  public UnmodifiableListIterator<E> listIterator() {
    return listIterator(0);
  }

  @SuppressWarnings("unchecked")
  @Override
  public UnmodifiableListIterator<E> listIterator(int index) {
    checkPositionIndex(index, size());
    if (isEmpty()) {
      return (UnmodifiableListIterator<E>) EMPTY_ITR;
    } else {
      return new Itr<E>(this, index);

   */
  // Casting to any type is safe since there are no actual elements.
  @SuppressWarnings("unchecked")
  static <T extends @Nullable Object> UnmodifiableListIterator<T> emptyListIterator() {
    return (UnmodifiableListIterator<T>) ArrayItr.EMPTY;
  }

  /**
   * This is an enum singleton rather than an anonymous class so ProGuard can figure out it's only
   * referenced by emptyModifiableIterator().

 * </ul>
 *
 * <h2>Abstract implementations</h2>
 *
 * <ul>
 *   <li>{@link AbstractIterator}
 *   <li>{@link AbstractSequentialIterator}
 *   <li>{@link UnmodifiableIterator}
 *   <li>{@link UnmodifiableListIterator}
 * </ul>
 *
 * <h2>Forwarding collections</h2>
 *
 * We provide implementations of collections that forward all method calls to a delegate collection