Helpers.addAll(elements, previousElements);
      Helpers.addAll(elements, Helpers.reverse(nextElements));
      return elements;
    }
  }

  public enum KnownOrder {
    KNOWN_ORDER,
    UNKNOWN_ORDER
  }

  @SuppressWarnings("unchecked") // TODO(cpovirk): Stop using arrays.
  AbstractIteratorTester(
      int steps,
      Iterable<E> elementsToInsertIterable,

      Helpers.addAll(elements, previousElements);
      Helpers.addAll(elements, Helpers.reverse(nextElements));
      return elements;
    }
  }

  public enum KnownOrder {
    KNOWN_ORDER,
    UNKNOWN_ORDER
  }

  @SuppressWarnings("unchecked") // TODO(cpovirk): Stop using arrays.
  AbstractIteratorTester(
      int steps,
      Iterable<E> elementsToInsertIterable,

 *
 * <ul>
 *   <li>As a method return type, as an alternative to returning {@code null} to indicate that no
 *       value was available
 *   <li>To distinguish between "unknown" (for example, not present in a map) and "known to have no
 *       value" (present in the map, with value {@code Optional.absent()})
 *   <li>To wrap nullable references for storage in a collection that does not support {@code null}

    IteratorTester<T> tester =
        new IteratorTester<T>(
            steps,
            IteratorFeature.MODIFIABLE,
            Lists.newLinkedList(values),
            IteratorTester.KnownOrder.UNKNOWN_ORDER) {
          private @Nullable MinMaxPriorityQueue<T> mmHeap;

          @Override
          protected Iterator<T> newTargetIterator() {
            mmHeap = MinMaxPriorityQueue.create(values);

 *
 * <ul>
 *   <li>As a method return type, as an alternative to returning {@code null} to indicate that no
 *       value was available
 *   <li>To distinguish between "unknown" (for example, not present in a map) and "known to have no
 *       value" (present in the map, with value {@code Optional.absent()})
 *   <li>To wrap nullable references for storage in a collection that does not support {@code null}

            .withFeatures(ALLOWS_ANY_NULL_QUERIES, SERIALIZABLE, KNOWN_ORDER, CollectionSize.ANY)
            .createTestSuite());
    suite.addTest(
        ListMultimapTestSuiteBuilder.using(new ImmutableListMultimapCopyOfEntriesGenerator())
            .named("ImmutableListMultimap.copyOf[Iterable<Entry>]")
            .withFeatures(ALLOWS_ANY_NULL_QUERIES, SERIALIZABLE, KNOWN_ORDER, CollectionSize.ANY)
            .createTestSuite());

            .withFeatures(ALLOWS_ANY_NULL_QUERIES, KNOWN_ORDER, SERIALIZABLE, CollectionSize.ANY)
            .createTestSuite());
    suite.addTest(
        SetMultimapTestSuiteBuilder.using(new ImmutableSetMultimapCopyOfEntriesGenerator())
            .named("ImmutableSetMultimap.copyOf[Iterable<Entry>]")
            .withFeatures(ALLOWS_ANY_NULL_QUERIES, KNOWN_ORDER, SERIALIZABLE, CollectionSize.ANY)
            .createTestSuite());

      @Override
      protected Iterator<String> newTargetIterator() {
        return of("a").iterator();
      }
    }.test();
  }

  @GwtIncompatible // slow (~30s)
  public void testIterator_general() {
    new IteratorTester<String>(
        5, UNMODIFIABLE, asList("a", "b", "c"), IteratorTester.KnownOrder.KNOWN_ORDER) {
      @Override

      @Override
      protected Iterator<String> newTargetIterator() {
        return of("a").iterator();
      }
    }.test();
  }

  @GwtIncompatible // slow (~30s)
  public void testIterator_general() {
    new IteratorTester<String>(
        5, UNMODIFIABLE, asList("a", "b", "c"), IteratorTester.KnownOrder.KNOWN_ORDER) {
      @Override

            .withFeatures(
                CollectionSize.ANY,
                CollectionFeature.SERIALIZABLE_INCLUDING_VIEWS,
                CollectionFeature.KNOWN_ORDER,
                MapFeature.REJECTS_DUPLICATES_AT_CREATION,
                MapFeature.ALLOWS_ANY_NULL_QUERIES)
            .named("ImmutableSortedMap")
            .createTestSuite());
    suite.addTest(