*
 * <p>This class does not implement {@link java.util.RandomAccess}. If the delegate supports random
 * access, the {@code ForwardingList} subclass should implement the {@code RandomAccess} interface.
 *
 * <p><b>Warning:</b> The methods of {@code ForwardingList} forward <b>indiscriminately</b> to the
 * methods of the delegate. For example, overriding {@link #add} alone <b>will not</b> change the

import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Tests for {@code ForwardingList}.
 *
 * @author Robert Konigsberg
 * @author Louis Wasserman
 */
@NullUnmarked
public class ForwardingListTest extends TestCase {
  static final class StandardImplForwardingList<T> extends ForwardingList<T> {
    private final List<T> backingList;

    StandardImplForwardingList(List<T> backingList) {

 * JDK's collection wrappers, such as {@link java.util.Collections#unmodifiableCollection}. Use an
 * interface-specific subclass of {@code ForwardingObject}, such as {@link ForwardingList}, to
 * preserve equality behavior, or override {@code equals} directly.
 *
 * <p>The {@code toString} method is forwarded to the delegate. Although this class does not

 * JDK's collection wrappers, such as {@link java.util.Collections#unmodifiableCollection}. Use an
 * interface-specific subclass of {@code ForwardingObject}, such as {@link ForwardingList}, to
 * preserve equality behavior, or override {@code equals} directly.
 *
 * <p>The {@code toString} method is forwarded to the delegate. Although this class does not

    protected Set<V> delegate() {
      return emptySet();
    }
  }

  private static final class AddRejectingList<
          K extends @Nullable Object, V extends @Nullable Object>
      extends ForwardingList<V> {
    @ParametricNullness final K key;

    AddRejectingList(@ParametricNullness K key) {
      this.key = key;
    }

    @Override
    public boolean add(@ParametricNullness V v) {

    protected Set<V> delegate() {
      return emptySet();
    }
  }

  private static final class AddRejectingList<
          K extends @Nullable Object, V extends @Nullable Object>
      extends ForwardingList<V> {
    @ParametricNullness final K key;

    AddRejectingList(@ParametricNullness K key) {
      this.key = key;
    }

    @Override
    public boolean add(@ParametricNullness V v) {