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

/**
 * Tests for {@code ForwardingSortedMap}.
 *
 * @author Robert KonigsbergSortedMapFeature
 */
@NullUnmarked
public class ForwardingSortedMapTest extends TestCase {
  static class StandardImplForwardingSortedMap<K, V> extends ForwardingSortedMap<K, V> {
    private final SortedMap<K, V> backingSortedMap;

 *
 * @author Louis Wasserman
 * @since 12.0
 */
@GwtIncompatible
public abstract class ForwardingNavigableMap<K extends @Nullable Object, V extends @Nullable Object>
    extends ForwardingSortedMap<K, V> implements NavigableMap<K, V> {

  /** Constructor for use by subclasses. */
  protected ForwardingNavigableMap() {}

  @Override
  protected abstract NavigableMap<K, V> delegate();

  @Override

 *
 * @author Louis Wasserman
 * @since 12.0
 */
@GwtIncompatible
public abstract class ForwardingNavigableMap<K extends @Nullable Object, V extends @Nullable Object>
    extends ForwardingSortedMap<K, V> implements NavigableMap<K, V> {

  /** Constructor for use by subclasses. */
  protected ForwardingNavigableMap() {}

  @Override
  protected abstract NavigableMap<K, V> delegate();

  @Override