* ForwardingMap#clear}, {@link ForwardingMap#containsKey}, {@link ForwardingMap#isEmpty}, {@link
   * ForwardingMap#remove}, {@link ForwardingMap#size}, and the {@link Set#iterator} method of
   * {@link ForwardingMap#entrySet}. In many cases, you may wish to override {@link
   * ForwardingMap#keySet} to forward to this implementation or a subclass thereof.
   *

  // to a superclass.

  public MapsTransformValuesUnmodifiableIteratorTest() {
    super(true, true, false /*supportsPut*/, true, true, false);
  }

  private static class UnmodifiableIteratorMap<K, V> extends ForwardingMap<K, V> {
    final Map<K, V> delegate;

    UnmodifiableIteratorMap(Map<K, V> delegate) {
      this.delegate = delegate;
    }

    @Override
    protected Map<K, V> delegate() {
      return delegate;