* @param <OutElementT> the element type of the output spliterators
   */
  static final class FlatMapSpliteratorOfObject<
          InElementT extends @Nullable Object, OutElementT extends @Nullable Object>
      extends FlatMapSpliterator<InElementT, OutElementT, Spliterator<OutElementT>> {
    FlatMapSpliteratorOfObject(
        @Nullable Spliterator<OutElementT> prefix,
        Spliterator<InElementT> from,

   * function}.
   */
  static <InElementT extends @Nullable Object, OutElementT extends @Nullable Object>
      Spliterator<OutElementT> map(
          Spliterator<InElementT> fromSpliterator,
          Function<? super InElementT, ? extends OutElementT> function) {
    checkNotNull(fromSpliterator);
    checkNotNull(function);
    return new Spliterator<OutElementT>() {

      @Override