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
   * equal to the element that preceded it, according to the specified comparator. Note that this is

  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
   * equal to the element that preceded it, according to the specified comparator. Note that this is

    assertTrue(Comparators.isInStrictOrder(asList(0, 3, 5, 9), Ordering.natural()));
    assertFalse(Comparators.isInStrictOrder(asList(0, 0, 3, 3), Ordering.natural()));
    assertTrue(Comparators.isInStrictOrder(asList(0, 3), Ordering.natural()));
    assertTrue(Comparators.isInStrictOrder(Collections.singleton(1), Ordering.natural()));

  final Comparator<? super T>[] comparators;

  @SuppressWarnings("unchecked") // Generic array creation
  CompoundOrdering(Comparator<? super T> primary, Comparator<? super T> secondary) {
    this.comparators = (Comparator<? super T>[]) new Comparator<?>[] {primary, secondary};
  }

  @SuppressWarnings("unchecked") // Generic array creation
  CompoundOrdering(Iterable<? extends Comparator<? super T>> comparators) {

  final Comparator<? super T>[] comparators;

  @SuppressWarnings("unchecked") // Generic array creation
  CompoundOrdering(Comparator<? super T> primary, Comparator<? super T> secondary) {
    this.comparators = (Comparator<? super T>[]) new Comparator<?>[] {primary, secondary};
  }

  @SuppressWarnings("unchecked") // Generic array creation
  CompoundOrdering(Iterable<? extends Comparator<? super T>> comparators) {

   * there is no need to use this method.
   *
   * @param comparator the comparator that defines the order
   * @return comparator itself if it is already an {@code Ordering}; otherwise an ordering that
   *     wraps that comparator
   */
  @GwtCompatible(serializable = true)
  public static <T extends @Nullable Object> Ordering<T> from(Comparator<T> comparator) {
    return (comparator instanceof Ordering)
        ? (Ordering<T>) comparator

  }

  /**
   * Creates an empty {@code TreeMultimap} instance using explicit comparators. Neither comparator
   * may be null; use {@link Ordering#natural()} to specify natural order.
   *
   * @param keyComparator the comparator that determines the key ordering
   * @param valueComparator the comparator that determines the value ordering
   */

  }

  @Override
  ImmutableSortedSet<E> delegateCollection() {
    return (ImmutableSortedSet<E>) super.delegateCollection();
  }

  @Override
  public Comparator<? super E> comparator() {
    return delegateCollection().comparator();
  }

  // Override indexOf() and lastIndexOf() to be O(log N) instead of O(N).

  @GwtIncompatible // ImmutableSortedSet.indexOf

  }

  /**
   * Creates an empty {@code TreeMultimap} instance using explicit comparators. Neither comparator
   * may be null; use {@link Ordering#natural()} to specify natural order.
   *
   * @param keyComparator the comparator that determines the key ordering
   * @param valueComparator the comparator that determines the value ordering
   */

  private final Comparator<? super C> columnComparator;

  private static class Factory<C, V> implements Supplier<TreeMap<C, V>>, Serializable {
    final Comparator<? super C> comparator;

    Factory(Comparator<? super C> comparator) {
      this.comparator = comparator;
    }

    @Override
    public TreeMap<C, V> get() {
      return new TreeMap<>(comparator);
    }