while ( chld.hasNext() ) {

                    try ( SmbResource next = chld.next() ) {
                        if ( next.isDirectory() ) {
                            try (CloseableIterator<SmbResource> children = next.children()) {
                            }
                        }
                        names.add(next.getName());
                    }
                }
            }
        }

  @CheckForNull
  public abstract C previous(C value);

  /**
   * Returns a signed value indicating how many nested invocations of {@link #next} (if positive) or
   * {@link #previous} (if negative) are needed to reach {@code end} starting from {@code start}.
   * For example, if {@code end = next(next(next(start)))}, then {@code distance(start, end) == 3}
   * and {@code distance(end, start) == -3}. As well, {@code distance(a, a)} is always zero.
   *

   * part of the smeared hash of the element not covered by the hashtable mask, whereas the low bits
   * are the "next" pointer (pointing to the next entry in the bucket chain), which will always be
   * less than or equal to the hashtable mask.
   *
   * <pre>
   * hash  = aaaaaaaa
   * mask  = 00000fff
   * next  = 00000bbb
   * entry = aaaaabbb
   * </pre>
   *

        protected N computeNext() {
          for (N next = visitNext(horizon); next != null; next = visitNext(horizon)) {
            Iterator<? extends N> successors = successorFunction.successors(next).iterator();
            if (!successors.hasNext()) {
              return next;
            }
            horizon.addFirst(successors);
            ancestorStack.push(next);
          }

      }

      @Override
      @ParametricNullness
      public E next() {
        final Map.Entry<E, Count> mapEntry = backingEntries.next();
        toRemove = mapEntry;
        return mapEntry.getKey();
      }

      @Override
      public void remove() {
        checkState(toRemove != null, "no calls to next() since the last call to remove()");
        size -= toRemove.getValue().getAndSet(0);

      return next != null;
    }

    @Override
    @ParametricNullness
    public K next() {
      checkForConcurrentModification();
      if (next == null) {
        throw new NoSuchElementException();
      }
      current = next;
      seenKeys.add(current.key);
      do { // skip ahead to next unseen key
        next = next.next;

                return Integer.valueOf(from);
              }
            });

    Iterator<Integer> resultIterator = result.iterator();
    resultIterator.next();

    try {
      resultIterator.next();
      fail("Expected NFE");
    } catch (NumberFormatException expected) {
    }
  }

  public void testNullFriendlyTransform() {

    int i = 0;
    while (expectedIterator.hasNext()) {
      Object expected = expectedIterator.next();

      assertTrue(
          "index " + i + " expected <" + expected + "., actual is exhausted",
          actualIterator.hasNext());

      Object actual = actualIterator.next();
      assertEquals("index " + i, expected, actual);
      i++;
    }
    if (actualIterator.hasNext()) {

  @CheckForNull
  public abstract C previous(C value);

  /**
   * Returns a signed value indicating how many nested invocations of {@link #next} (if positive) or
   * {@link #previous} (if negative) are needed to reach {@code end} starting from {@code start}.
   * For example, if {@code end = next(next(next(start)))}, then {@code distance(start, end) == 3}
   * and {@code distance(end, start) == -3}. As well, {@code distance(a, a)} is always zero.
   *

    Iterator<?> expectedIter = expected.iterator();
    Iterator<?> actualIter = actual.iterator();

    while (expectedIter.hasNext() && actualIter.hasNext()) {
      if (!equal(expectedIter.next(), actualIter.next())) {
        Assert.fail(
            "contents were not equal and in the same order: "
                + "expected = "
                + expected
                + ", actual = "
                + actual);