*
   * @since 11.0
   */
  @DoNotMock
  public static final class Builder<R, C, V> {
    private final List<Cell<R, C, V>> cells = new ArrayList<>();
    private @Nullable Comparator<? super R> rowComparator;
    private @Nullable Comparator<? super C> columnComparator;

    /**
     * Creates a new builder. The returned builder is equivalent to the builder generated by {@link
     * ImmutableTable#builder}.
     */

    assertEquals(multimap, copy);
  }

  private static final Comparator<Double> KEY_COMPARATOR = Ordering.natural();

  private static final Comparator<Double> VALUE_COMPARATOR =
      Ordering.<Double>natural().reverse().nullsFirst();

  /**
   * Test that creating one TreeMultimap from another does not copy the comparators from the source
   * TreeMultimap.
   */
  public void testCreateFromTreeMultimap() {

  /**
   * Creates a {@code MonitorBasedPriorityBlockingQueue} with the specified initial capacity that
   * orders its elements according to the specified comparator.
   *
   * @param initialCapacity the initial capacity for this priority queue
   * @param comparator the comparator that will be used to order this priority queue. If {@code
   *     null}, the {@linkplain Comparable natural ordering} of the elements will be used.

  Iterator<C> createColumnKeyIterator() {
    return new ColumnKeyIterator();
  }

  private final class ColumnKeyIterator extends AbstractIterator<C> {
    // Use the same map type to support TreeMaps with comparators that aren't
    // consistent with equals().
    final Map<C, V> seen = factory.get();
    final Iterator<Map<C, V>> mapIterator = backingMap.values().iterator();
    Iterator<Entry<C, V>> entryIterator = emptyIterator();

  Iterator<C> createColumnKeyIterator() {
    return new ColumnKeyIterator();
  }

  private final class ColumnKeyIterator extends AbstractIterator<C> {
    // Use the same map type to support TreeMaps with comparators that aren't
    // consistent with equals().
    final Map<C, V> seen = factory.get();
    final Iterator<Map<C, V>> mapIterator = backingMap.values().iterator();
    Iterator<Entry<C, V>> entryIterator = emptyIterator();

    Comparator<Comparable<?>> comparator = Ordering.natural().reverse();
    SortedSet<String> set =
        new ImmutableSortedSet.Builder<String>(comparator).add("a", "b", "c").build();
    SortedSet<String> copy = SerializableTester.reserializeAndAssert(set);
    assertTrue(elementsEqual(set, copy));
    assertEquals(set.comparator(), copy.comparator());
  }

  public void testReverseOrder() {

    // 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();

   * {@code comparator}.
   */
  public static boolean hasSameComparator(Comparator<?> comparator, Iterable<?> elements) {
    checkNotNull(comparator);
    checkNotNull(elements);
    Comparator<?> comparator2;
    if (elements instanceof SortedSet) {
      comparator2 = comparator((SortedSet<?>) elements);
    } else if (elements instanceof SortedIterable) {

    private final Comparator<? super E> comparator;

    public Builder(Comparator<? super E> comparator) {
      this.comparator = checkNotNull(comparator);
    }

    Builder(Comparator<? super E> comparator, int expectedSize) {
      super(expectedSize);
      this.comparator = checkNotNull(comparator);
    }

    @CanIgnoreReturnValue
    @Override
    public Builder<E> add(E element) {

   * 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) {