*/
  @GwtIncompatible // NavigableMap
  public static <K extends @Nullable Object, V extends @Nullable Object> NavigableMap<K, V> asMap(
      NavigableSet<K> set, Function<? super K, V> function) {
    return new NavigableAsMapView<>(set, function);
  }

  private static class AsMapView<K extends @Nullable Object, V extends @Nullable Object>
      extends ViewCachingAbstractMap<K, V> {

    private final Set<K> set;

   */
  @GwtIncompatible // NavigableMap
  public static <K extends @Nullable Object, V extends @Nullable Object> NavigableMap<K, V> asMap(
      NavigableSet<K> set, Function<? super K, V> function) {
    return new NavigableAsMapView<>(set, function);
  }

  private static class AsMapView<K extends @Nullable Object, V extends @Nullable Object>
      extends ViewCachingAbstractMap<K, V> {

    private final Set<K> set;