import java.util.TreeMap;

/**
 * Tests for {@link ForwardingSortedMap} using {@link MapInterfaceTest}.
 *
 * @author George van den Driessche
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault
public class ForwardingSortedMapImplementsMapTest extends SortedMapInterfaceTest<String, Integer> {

  private static class SimpleForwardingSortedMap<K, V> extends ForwardingSortedMap<K, V> {
    final SortedMap<K, V> delegate;

  }

  @GwtIncompatible // NavigableMap
  static class UnmodifiableNavigableMap<K extends @Nullable Object, V extends @Nullable Object>
      extends ForwardingSortedMap<K, V> implements NavigableMap<K, V>, Serializable {
    private final NavigableMap<K, ? extends V> delegate;

    UnmodifiableNavigableMap(NavigableMap<K, ? extends V> delegate) {
      this.delegate = delegate;

  }

  @GwtIncompatible // NavigableMap
  static class UnmodifiableNavigableMap<K extends @Nullable Object, V extends @Nullable Object>
      extends ForwardingSortedMap<K, V> implements NavigableMap<K, V>, Serializable {
    private final NavigableMap<K, ? extends V> delegate;

    UnmodifiableNavigableMap(NavigableMap<K, ? extends V> delegate) {
      this.delegate = delegate;