return using(generator);
  }

  private static final class DescendingTestMapGenerator<K, V>
      extends ForwardingTestMapGenerator<K, V> implements TestSortedMapGenerator<K, V> {
    DescendingTestMapGenerator(TestSortedMapGenerator<K, V> delegate) {
      super(delegate);
    }

    @Override
    public NavigableMap<K, V> create(Object... entries) {