* natural ordering. The sorted multisets use {@link Ordering#natural()} as the comparator. This
   * method provides more type-safety than {@link #builder}, as it can be called only for classes
   * that implement {@link Comparable}.
   *
   * <p>Note: the type parameter {@code E} extends {@code Comparable<?>} rather than {@code
   * Comparable<? super E>} as a workaround for javac <a

  // think tip it over into being worthwhile.
  public static <T extends @Nullable Object, S extends T> Comparator<Iterable<S>> lexicographical(
      Comparator<T> comparator) {
    return new LexicographicalOrdering<S>(checkNotNull(comparator));
  }

  /**
   * Returns {@code true} if each element in {@code iterable} after the first is greater than or

  }

  /**
   * This method returns a {@code ImmutableSortedMap}, consisting of the entries whose keys are less
   * than {@code toKey}.
   *
   * <p>The {@link SortedMap#headMap} documentation states that a submap of a submap throws an
   * {@link IllegalArgumentException} if passed a {@code toKey} greater than an earlier {@code
   * toKey}. However, this method doesn't throw an exception in that situation, but instead keeps

   * IllegalArgumentException} if passed a {@code fromElement} smaller than an earlier {@code
   * fromElement}. However, this method doesn't throw an exception in that situation, but instead
   * keeps the original {@code fromElement}. Similarly, this method keeps the original {@code
   * toElement}, instead of throwing an exception, if passed a {@code toElement} greater than an
   * earlier {@code toElement}.
   */
  @Override

   * Elements are added in encounter order.
   *
   * <p>If the mapped elements contain duplicates (according to {@link Object#equals}), the element
   * will be added more than once, with the count summed over all appearances of the element.
   *
   * <p>Note that {@code stream.collect(toMultiset(function, e -> 1, supplier))} is equivalent to

  /**
   * {@inheritDoc}
   *
   * <p>Because an inverse of a set multimap cannot contain multiple pairs with the same key and
   * value, this method returns an {@code ImmutableSetMultimap} rather than the {@code
   * ImmutableMultimap} specified in the {@code ImmutableMultimap} class.
   */
  @Override
  public ImmutableSetMultimap<V, K> inverse() {
    ImmutableSetMultimap<V, K> result = inverse;

     * Returns a newly-created immutable map, using the last value for any key that was added more
     * than once. The iteration order of the returned map is the order in which entries were
     * inserted into the builder, unless {@link #orderEntriesByValue} was called, in which case
     * entries are sorted by value. If a key was added more than once, it appears in iteration order

   *
   * <p>If {@code expectedSize} is exactly the number of entries added to the builder before {@link
   * Builder#build} is called, the builder is likely to perform better than an unsized {@link
   * #builder()} would have.
   *
   * <p>It is not specified if any performance benefits apply if {@code expectedSize} is close to,
   * but not exactly, the number of entries added to the builder.
   *

   * instead.
   *
   * <p><b>Note:</b> If {@code elements} is a {@code SortedSet} with an explicit comparator, this
   * method has different behavior than {@link TreeSet#TreeSet(SortedSet)}, which returns a {@code
   * TreeSet} with that comparator.
   *
   * <p><b>Note:</b> this method is now unnecessary and should be treated as deprecated. Instead,

    return (Collector) ONLY_ELEMENT;
  }

  /**
   * This atrocity is here to let us report several of the elements in the stream if there were more
   * than one, not just two.
   */
  private static final class ToOptionalState {
    static final int MAX_EXTRAS = 4;

    @CheckForNull Object element;
    List<Object> extras;

    ToOptionalState() {