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
   * always true when the iterable has fewer than two elements.
   */

   * should be identical to the one the user passed in. We touch only the
   * "secret" comparator used by the delegate implementation.
   */

  private static <K, V> SortedMap<K, V> newModifiableDelegate(Comparator<? super K> comparator) {
    return newTreeMap(nullAccepting(comparator));
  }

  private static <E> Comparator<@Nullable E> nullAccepting(Comparator<E> comparator) {

   *
   * @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
   */
  public static <T extends @Nullable Object> Ordering<T> from(Comparator<T> comparator) {
    return (comparator instanceof Ordering)
        ? (Ordering<T>) comparator
        : new ComparatorOrdering<T>(comparator);

      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
   * always true when the iterable has fewer than two elements.
   */

   * ClassCastException}.
   *
   * @param comparator the comparator that will be used to sort this multiset. A null value
   *     indicates that the elements' <i>natural ordering</i> should be used.
   */
  @SuppressWarnings("unchecked")
  public static <E extends @Nullable Object> TreeMultiset<E> create(
      @Nullable Comparator<? super E> comparator) {
    return (comparator == null)

  public static <K, V> ImmutableSortedMap<K, V> copyOfSorted(SortedMap<K, ? extends V> map) {
    Comparator<? super K> comparator = map.comparator();
    if (comparator == null) {
      // If map has a null comparator, the keys should have a natural ordering,
      // even though K doesn't explicitly implement Comparable.
      comparator = (Comparator<? super K>) NATURAL_ORDER;
    }
    if (map instanceof ImmutableSortedMap) {

  public static <K, V> ImmutableSortedMap<K, V> copyOfSorted(SortedMap<K, ? extends V> map) {
    Comparator<? super K> comparator = map.comparator();
    if (comparator == null) {
      // If map has a null comparator, the keys should have a natural ordering,
      // even though K doesn't explicitly implement Comparable.
      comparator = (Comparator<? super K>) NATURAL_ORDER;
    }
    if (map instanceof ImmutableSortedMap) {

  }

  @Override
  public void clear() {
    delegate.clear();
  }

  @Override
  public Comparator<? super E> comparator() {
    Comparator<? super E> comparator = delegate.comparator();
    if (comparator != null) {
      return comparator;
    }
    return NATURAL_ORDER;
  }

  @Override
  public boolean contains(Object object) {

    assertMapEquals(copy, "two", 2, "three", 3, "one", 1);
    assertThat(ImmutableSortedMap.copyOf(copy, comparator)).isSameInstanceAs(copy);
    assertThat(copy.comparator()).isEqualTo(comparator);
  }

  public void testCopyOfImmutableSortedSetDifferentComparator() {
    Comparator<String> comparator = Ordering.<String>natural().reverse();

    // The VarHandle, Unsafe, or Java implementation.
    Comparator<byte[]> comparator = UnsignedBytes.lexicographicalComparator();
    Helpers.testComparator(comparator, ordered);
    assertThat(SerializableTester.reserialize(comparator)).isSameInstanceAs(comparator);

    // The Java implementation.
    Comparator<byte[]> javaImpl = UnsignedBytes.lexicographicalComparatorJavaImpl();