// second, then signals that it's reached the end of the data
    Iterator<Integer> iter =
        new AbstractIterator<Integer>() {
          private int rep;

          @Override
          public @Nullable Integer computeNext() {
            switch (rep++) {
              case 0:
                return 0;
              case 1:
                return 1;
              case 2:
                return endOfData();
              default:

    // second, then signals that it's reached the end of the data
    Iterator<Integer> iter =
        new AbstractIterator<Integer>() {
          private int rep;

          @Override
          public Integer computeNext() {
            switch (rep++) {
              case 0:
                return 0;
              case 1:
                return 1;
              case 2:
                return endOfData();
              default:

    // second, then signals that it's reached the end of the data
    Iterator<Integer> iter =
        new AbstractIterator<Integer>() {
          private int rep;

          @Override
          public Integer computeNext() {
            switch (rep++) {
              case 0:
                return 0;
              case 1:
                return 1;
              case 2:
                return endOfData();
              default:

    // second, then signals that it's reached the end of the data
    Iterator<Integer> iter =
        new AbstractIterator<Integer>() {
          private int rep;

          @Override
          public @Nullable Integer computeNext() {
            switch (rep++) {
              case 0:
                return 0;
              case 1:
                return 1;
              case 2:
                return endOfData();
              default:

      @Override
      protected @Nullable Integer computeNext(Integer previous) {
        return (previous == last) ? null : previous * 2;
      }
    };
  }

  private static class EmptyAbstractSequentialIterator<T> extends AbstractSequentialIterator<T> {

    public EmptyAbstractSequentialIterator() {
      super(null);
    }

    @Override
    protected T computeNext(T previous) {

      @Override
      protected @Nullable Integer computeNext(Integer previous) {
        return (previous == last) ? null : previous * 2;
      }
    };
  }

  private static class EmptyAbstractSequentialIterator<T> extends AbstractSequentialIterator<T> {

    public EmptyAbstractSequentialIterator() {
      super(null);
    }

    @Override
    protected T computeNext(T previous) {

          Set<N> seenNodes = new HashSet<>();
          return new AbstractIterator<N>() {
            @Override
            @CheckForNull
            protected N computeNext() {
              while (nodeConnections.hasNext()) {
                NodeConnection<N> nodeConnection = nodeConnections.next();
                boolean added = seenNodes.add(nodeConnection.node);

                  .iterator();
        }
      }
      return new AbstractIterator<Entry<Cut<C>, Range<C>>>() {
        @Override
        @CheckForNull
        protected Entry<Cut<C>, Range<C>> computeNext() {
          if (!backingItr.hasNext()) {
            return endOfData();
          }
          Range<C> range = backingItr.next();
          if (upperBoundWindow.upperBound.isLessThan(range.upperBound)) {

  private final Queue<T> queue;

  ConsumingQueueIterator(Queue<T> queue) {
    this.queue = checkNotNull(queue);
  }

  @Override
  @CheckForNull
  protected T computeNext() {
    // TODO(b/192579700): Use a ternary once it no longer confuses our nullness checker.
    if (queue.isEmpty()) {
      return endOfData();
    }
    return queue.remove();
  }

        // TODO(lowasser): consider making the entries live views
        return new AbstractIterator<Entry<E>>() {
          @Override
          @CheckForNull
          protected Entry<E> computeNext() {
            if (iterator1.hasNext()) {
              Entry<? extends E> entry1 = iterator1.next();
              E element = entry1.getElement();