* @since 14.0
   */
  @SuppressWarnings("nullness") // Unsafe, but we can't do much about it now.
  public final <V> ImmutableMap<@NonNull E, V> toMap(Function<? super E, V> valueFunction) {
    return Maps.toMap((Iterable<@NonNull E>) getDelegate(), valueFunction);
  }

  /**
   * Creates an index {@code ImmutableListMultimap} that contains the results of applying a

   * @since 14.0
   */
  @SuppressWarnings("nullness") // Unsafe, but we can't do much about it now.
  public final <V> ImmutableMap<@NonNull E, V> toMap(Function<? super E, V> valueFunction) {
    return Maps.toMap((Iterable<@NonNull E>) getDelegate(), valueFunction);
  }

  /**
   * Creates an index {@code ImmutableListMultimap} that contains the results of applying a