.testForwarding(
            SortedMap.class,
            new Function<SortedMap, SortedMap>() {
              @Override
              public SortedMap apply(SortedMap delegate) {
                return wrap(delegate);
              }
            });
  }

  public void testEquals() {
    SortedMap<Integer, String> map1 = ImmutableSortedMap.of(1, "one");

    extends AbstractSortedSetMultimap<K, V> {

  AbstractSortedKeySortedSetMultimap(SortedMap<K, Collection<V>> map) {
    super(map);
  }

  @Override
  public SortedMap<K, Collection<V>> asMap() {
    return (SortedMap<K, Collection<V>>) super.asMap();
  }

  @Override
  SortedMap<K, Collection<V>> backingMap() {
    return (SortedMap<K, Collection<V>>) super.backingMap();
  }

  @Override

  @Override
  protected SortedMap<String, Integer> makeEmptyMap() {
    return new SimpleForwardingSortedMap<>(
        new TreeMap<String, Integer>(Ordering.<String>natural().nullsFirst()));
  }

  @Override
  protected SortedMap<String, Integer> makePopulatedMap() {
    final SortedMap<String, Integer> sortedMap = makeEmptyMap();
    sortedMap.put("one", 1);
    sortedMap.put("two", 2);
    sortedMap.put("three", 3);

import com.google.common.annotations.GwtCompatible;
import java.util.SortedMap;

@GwtCompatible
@ElementTypesAreNonnullByDefault
public class FilteredSortedMapTest extends AbstractFilteredMapTest {
  @Override
  SortedMap<String, Integer> createUnfiltered() {
    return Maps.newTreeMap();
  }

  public void testFirstAndLastKeyFilteredMap() {
    SortedMap<String, Integer> unfiltered = createUnfiltered();

    extends MapDifference<K, V> {

  @Override
  SortedMap<K, V> entriesOnlyOnLeft();

  @Override
  SortedMap<K, V> entriesOnlyOnRight();

  @Override
  SortedMap<K, V> entriesInCommon();

  @Override
  SortedMap<K, ValueDifference<V>> entriesDiffering();

   * returns a {@link SortedMap}, instead of the {@link Map} specified in the {@link Table}
   * interface.
   *
   * @since 10.0 (<a href="https://github.com/google/guava/wiki/Compatibility" >mostly
   *     source-compatible</a> since 7.0)
   */
  @Override
  public SortedMap<C, V> row(R rowKey) {
    return new TreeRow(rowKey);
  }

  private class TreeRow extends Row implements SortedMap<C, V> {

    extends ForwardingMap<K, V> implements SortedMap<K, V> {
  // TODO(lowasser): identify places where thread safety is actually lost

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

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

  @Override
  @CheckForNull
  public Comparator<? super K> comparator() {

  @Override
  protected SortedMap<String, Integer> makeEmptyMap() {
    return new SimpleForwardingSortedMap<>(
        new TreeMap<String, Integer>(Ordering.<String>natural().nullsFirst()));
  }

  @Override
  protected SortedMap<String, Integer> makePopulatedMap() {
    final SortedMap<String, Integer> sortedMap = makeEmptyMap();
    sortedMap.put("one", 1);
    sortedMap.put("two", 2);
    sortedMap.put("three", 3);

    return SortedMapTestSuiteBuilder.using(
            new TestStringSortedMapGenerator() {
              @Override
              protected SortedMap<String, String> create(Entry<String, String>[] entries) {
                SortedMap<String, String> map = populate(new TreeMap<String, String>(), entries);
                return Collections.checkedSortedMap(map, String.class, String.class);
              }

    }

    @Override
    public SortedMap<K, V> subMap(K fromKey, K toKey) {
      return delegate().subMap(fromKey, true, toKey, false);
    }

    @Override
    public NavigableMap<K, V> tailMap(K fromKey, boolean inclusive) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate().tailMap(fromKey, inclusive);
    }

    @Override
    public SortedMap<K, V> tailMap(K fromKey) {