`UnmodifiableMultimap.forEach` uses the `Multimap.forEach` default implementation which involves listing entries, and creating a new lambda instead of simply passing the BiConsumer through to the protected instance. This is safe to pass directly though because `forEach(BiConsumer)` is a read-only operation.
* Returns an ordering which treats all values as equal, indicating "no ordering." Passing this
   * ordering to any <i>stable</i> sort algorithm results in no change to the order of elements.
   * Note especially that {@link #sortedCopy} and {@link #immutableSortedCopy} are stable, and in
   * the returned instance these are implemented by simply copying the source list.
   *
   * <p>Example:
   *
   * <pre>{@code
   * Ordering.allEqual().nullsLast().sortedCopy(
   *     asList(t, null, e, s, null, t, null))
   * }</pre>
   *
   * <p>Assuming {@code t}, {@code e} and {@code s} are non-null, this returns {@code [t, e, s, t,
   * null, null, null]} regardless of the true comparison order of those three values (which might
   * not even implement {@link Comparable} at all).
   *
   * <p><b>Warning:</b> by definition, this comparator is not <i>consistent with equals</i> (as
   * defined {@linkplain Comparator here}). Avoid its use in APIs, such as {@link
   * TreeSet#TreeSet(Comparator)}, where such consistency is expected.
   *
   * <p>The returned comparator is serializable.
   *
   * <p><b>Java 8 users:</b> Use the lambda expression {@code (a, b) -> 0} instead (in certain cases
   * you may need to cast that to {@code Comparator<YourType>}).
   *
   * @since 13.0
   */
  @GwtCompatible(serializable = true)
  @SuppressWarnings("unchecked")
  public static Ordering<Object> allEqual() {