* {@code k.equals(k2)} implies that {@code k2} is also of type {@code K}. Using a key type for
   * which this may not hold, such as {@code ArrayList}, may risk a {@code ClassCastException} when
   * calling methods on the resulting map view.
   *
   * @since 14.0
   */
  public static <K extends @Nullable Object, V extends @Nullable Object> Map<K, V> asMap(
      Set<K> set, Function<? super K, V> function) {