4,
        MODIFIABLE,
        getSubjectGenerator().order(asList(e0(), e1(), e1(), e2())),
        IteratorTester.KnownOrder.KNOWN_ORDER) {
      @Override
      protected Iterator<E> newTargetIterator() {
        return getSubjectGenerator().create(e0(), e1(), e1(), e2()).iterator();
      }
    }.test();
  }

  @CollectionFeature.Require(value = SUPPORTS_ITERATOR_REMOVE, absent = KNOWN_ORDER)

 * set would be sufficient to expose any possible bug. Brute force is simpler.
 *
 * <p>To use this class the concrete subclass must implement the {@link
 * IteratorTester#newTargetIterator()} method. This is because it's impossible to test an Iterator
 * without changing its state, so the tester needs a steady supply of fresh Iterators.
 *

        4,
        MODIFIABLE,
        getSubjectGenerator().order(asList(e0(), e1(), e1(), e2())),
        IteratorTester.KnownOrder.KNOWN_ORDER) {
      @Override
      protected Iterator<E> newTargetIterator() {
        return getSubjectGenerator().create(e0(), e1(), e1(), e2()).iterator();
      }
    }.test();
  }

  @CollectionFeature.Require(value = SUPPORTS_ITERATOR_REMOVE, absent = KNOWN_ORDER)

        listListIteratorTesterNumIterations(),
        singleton(e4()),
        features,
        copyToList(getOrderedElements()),
        0) {
      @Override
      protected ListIterator<E> newTargetIterator() {
        resetCollection();
        return getList().listIterator();
      }

      @Override
      protected void verify(List<E> elements) {
        expectContents(elements);
      }
    }.test();

 * set would be sufficient to expose any possible bug. Brute force is simpler.
 *
 * <p>To use this class the concrete subclass must implement the {@link
 * IteratorTester#newTargetIterator()} method. This is because it's impossible to test an Iterator
 * without changing its state, so the tester needs a steady supply of fresh Iterators.
 *

    PeekingIteratorTester(Collection<T> master) {
      super(master.size() + 3, MODIFIABLE, master, IteratorTester.KnownOrder.KNOWN_ORDER);
      this.master = master;
    }

    @Override
    protected Iterator<T> newTargetIterator() {
      // make copy from master to verify later
      targetList = Lists.newArrayList(master);
      Iterator<T> iterator = targetList.iterator();
      return Iterators.peekingIterator(iterator);
    }

    Helpers.addAll(list, iteratorStimuli());
    Helpers.addAll(list, listIteratorStimuli());
    return list;
  }

  @Override
  protected abstract ListIterator<E> newTargetIterator();

    Helpers.addAll(list, iteratorStimuli());
    Helpers.addAll(list, listIteratorStimuli());
    return list;
  }

  @Override
  protected abstract ListIterator<E> newTargetIterator();

  public void testDoublerExhaustive() {
    new IteratorTester<Integer>(
        3, UNMODIFIABLE, ImmutableList.of(1, 2), IteratorTester.KnownOrder.KNOWN_ORDER) {
      @Override
      protected Iterator<Integer> newTargetIterator() {
        return newDoubler(1, 2);
      }
    }.test();
  }

  public void testDoubler() {
    Iterable<Integer> doubled =
        new Iterable<Integer>() {
          @Override

        listListIteratorTesterNumIterations(),
        singleton(e4()),
        features,
        copyToList(getOrderedElements()),
        0) {
      @Override
      protected ListIterator<E> newTargetIterator() {
        resetCollection();
        return getList().listIterator();
      }

      @Override
      protected void verify(List<E> elements) {
        expectContents(elements);
      }
    }.test();