@Override
  public NavigableMap<K, V> descendingMap() {
    return new DescendingMap();
  }

  private final class DescendingMap extends Maps.DescendingMap<K, V> {
    @Override
    NavigableMap<K, V> forward() {
      return AbstractNavigableMap.this;
    }

    @Override
    Iterator<Entry<K, V>> entryIterator() {
      return descendingEntryIterator();
    }
  }

  @Override
  public NavigableMap<K, V> descendingMap() {
    return new DescendingMap();
  }

  private final class DescendingMap extends Maps.DescendingMap<K, V> {
    @Override
    NavigableMap<K, V> forward() {
      return AbstractNavigableMap.this;
    }

    @Override
    Iterator<Entry<K, V>> entryIterator() {
      return descendingEntryIterator();
    }
  }