// 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();

   * 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)

   * 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)

    Ordering<@Nullable Object> comparator = Ordering.allEqual();
    assertSame(comparator, comparator.reverse());

    assertEquals(0, comparator.compare(null, null));
    assertEquals(0, comparator.compare(new Object(), new Object()));
    assertEquals(0, comparator.compare("apples", "oranges"));
    assertSame(comparator, reserialize(comparator));
    assertEquals("Ordering.allEqual()", comparator.toString());

    Ordering<@Nullable Object> comparator = Ordering.allEqual();
    assertSame(comparator, comparator.reverse());

    assertEquals(0, comparator.compare(null, null));
    assertEquals(0, comparator.compare(new Object(), new Object()));
    assertEquals(0, comparator.compare("apples", "oranges"));
    assertSame(comparator, reserialize(comparator));
    assertEquals("Ordering.allEqual()", comparator.toString());

   * the given {@code comparator}.
   *
   * @see #testComparator(Comparator, List)
   */
  public static <T extends @Nullable Object> void testComparator(
      Comparator<? super T> comparator, T... valuesInExpectedOrder) {
    testComparator(comparator, asList(valuesInExpectedOrder));
  }

  /**

   * the given {@code comparator}.
   *
   * @see #testComparator(Comparator, List)
   */
  public static <T extends @Nullable Object> void testComparator(
      Comparator<? super T> comparator, T... valuesInExpectedOrder) {
    testComparator(comparator, asList(valuesInExpectedOrder));
  }

  /**

            new byte[] {GREATEST, GREATEST, GREATEST});

    Comparator<byte[]> comparator = SignedBytes.lexicographicalComparator();
    Helpers.testComparator(comparator, ordered);
  }

  @J2ktIncompatible
  @GwtIncompatible // SerializableTester
  public void testLexicographicalComparatorSerializable() {
    Comparator<byte[]> comparator = SignedBytes.lexicographicalComparator();

    @LazyInit private transient @Nullable Comparator<? super K> comparator;

    @SuppressWarnings("unchecked")
    @Override
    public Comparator<? super K> comparator() {
      Comparator<? super K> result = comparator;
      if (result == null) {
        Comparator<? super K> forwardCmp = forward().comparator();
        if (forwardCmp == null) {
          forwardCmp = (Comparator) Ordering.natural();
        }

      map.put(entry.getKey(), entry.getValue());
    }
    return map;
  }

  static <T> Comparator<T> arbitraryNullFriendlyComparator() {
    return new NullFriendlyComparator<>();
  }

  private static final class NullFriendlyComparator<T> implements Comparator<T>, Serializable {
    @Override
    public int compare(T left, T right) {