UNKNOWN_ORDER
  }

  @SuppressWarnings("unchecked") // TODO(cpovirk): Stop using arrays.
  AbstractIteratorTester(
      int steps,
      Iterable<E> elementsToInsertIterable,
      Iterable<? extends IteratorFeature> features,
      Iterable<E> expectedElements,
      KnownOrder knownOrder,
      int startIndex) {
    // periodically we should manually try (steps * 3 / 2) here; all tests but

    @Override
    public SampleElements<String> sampleValues() {
      return new SampleElements<>("january", "february", "march", "april", "may");
    }

    @Override
    public Collection<String> createCollection(Iterable<? extends String> values) {
      return Lists.newArrayList(values);
    }

    @Override
    public SampleElements<Entry<String, String>> samples() {
      return new SampleElements<>(

  }

  @Override
  public Set<V> removeAll(@Nullable Object key) {
    return (Set<V>) super.removeAll(key);
  }

  @Override
  public Set<V> replaceValues(@ParametricNullness K key, Iterable<? extends V> values) {
    return (Set<V>) super.replaceValues(key, values);
  }

  @Override
  Set<Entry<K, V>> createEntries() {
    return Sets.filter(unfiltered().entries(), entryPredicate());
  }

    public String toString() {
      return "CharSource.empty()";
    }
  }

  private static final class ConcatenatedCharSource extends CharSource {

    private final Iterable<? extends CharSource> sources;

    ConcatenatedCharSource(Iterable<? extends CharSource> sources) {
      this.sources = checkNotNull(sources);
    }

    @Override
    public Reader openStream() throws IOException {

    public String toString() {
      return "CharSource.empty()";
    }
  }

  private static final class ConcatenatedCharSource extends CharSource {

    private final Iterable<? extends CharSource> sources;

    ConcatenatedCharSource(Iterable<? extends CharSource> sources) {
      this.sources = checkNotNull(sources);
    }

    @Override
    public Reader openStream() throws IOException {

  }

  @Override
  public Set<V> removeAll(@Nullable Object key) {
    return (Set<V>) super.removeAll(key);
  }

  @Override
  public Set<V> replaceValues(@ParametricNullness K key, Iterable<? extends V> values) {
    return (Set<V>) super.replaceValues(key, values);
  }

  @Override
  public Set<Entry<K, V>> entries() {
    return (Set<Entry<K, V>>) super.entries();
  }

  @Override

  }

  @Override
  public final String[] createValueArray(int length) {
    return new String[length];
  }

  /** Returns the original element list, unchanged. */
  @Override
  public Iterable<Entry<String, String>> order(List<Entry<String, String>> insertionOrder) {
    return insertionOrder;
  }

  }

  @Override
  public final String[] createValueArray(int length) {
    return new String[length];
  }

  /** Returns the original element list, unchanged. */
  @Override
  public Iterable<Entry<String, String>> order(List<Entry<String, String>> insertionOrder) {
    return insertionOrder;
  }

  }

  @Override
  public Set<E> incidentEdges() {
    return new AbstractSet<E>() {
      @Override
      public UnmodifiableIterator<E> iterator() {
        Iterable<E> incidentEdges =
            (selfLoopCount == 0)
                ? Iterables.concat(inEdgeMap.keySet(), outEdgeMap.keySet())
                : Sets.union(inEdgeMap.keySet(), outEdgeMap.keySet());
        return Iterators.unmodifiableIterator(incidentEdges.iterator());

    return mapEntry("~~ a", "above view");
  }

  @Override
  public Entry<String, String> aboveSamplesGreater() {
    return mapEntry("~~ b", "above view");
  }

  @Override
  public Iterable<Entry<String, String>> order(List<Entry<String, String>> insertionOrder) {
    return orderEntriesByKey(insertionOrder);
  }

  @Override