*/
  private static <N> boolean subgraphHasCycle(
      Graph<N> graph, Map<Object, NodeVisitState> visitedNodes, N startNode) {
    Deque<NodeAndRemainingSuccessors<N>> stack = new ArrayDeque<>();
    stack.addLast(new NodeAndRemainingSuccessors<>(startNode));

    while (!stack.isEmpty()) {
      // To peek at the top two items, we need to temporarily remove one.

  public SampleElements<UnhashableObject> samples() {
    return new Unhashables();
  }

  @Override
  public T create(Object... elements) {
    UnhashableObject[] array = createArray(elements.length);
    int i = 0;
    for (Object e : elements) {
      array[i++] = (UnhashableObject) e;
    }
    return create(array);
  }

  /**

     */
    public static FileOutputStream create(final File file) {
        assertArgumentNotNull("file", file);

        try {
            return new FileOutputStream(file);
        } catch (final IOException e) {
            throw new IORuntimeException(e);
        }
    }

    /**
     * Flushes the {@link OutputStream}.
     *
     * @param out the output stream
     */

        super(message, cause);
    }

    /**
     * Constructs a new exception with the specified detail message.
     *
     * @param message the detail message.
     */
    public ExecutionTimeoutException(final String message) {
        super(message);
    }

    /**
     * Constructs a new exception with the specified cause.
     *

            _specification = new HpSpecification();
        }
        return _specification;
    }

    protected void assertQueryPurpose() {
    }

    protected void assertAggregationPurpose() {
    }

    protected void assertSpecifyPurpose() {
    }

    public static class HpSpecification {
        protected List<String> columnList = new ArrayList<>();

            _specification = new HpSpecification();
        }
        return _specification;
    }

    protected void assertQueryPurpose() {
    }

    protected void assertAggregationPurpose() {
    }

    protected void assertSpecifyPurpose() {
    }

    public static class HpSpecification {
        protected List<String> columnList = new ArrayList<>();

            _specification = new HpSpecification();
        }
        return _specification;
    }

    protected void assertQueryPurpose() {
    }

    protected void assertAggregationPurpose() {
    }

    protected void assertSpecifyPurpose() {
    }

    public static class HpSpecification {
        protected List<String> columnList = new ArrayList<>();

            _specification = new HpSpecification();
        }
        return _specification;
    }

    protected void assertQueryPurpose() {
    }

    protected void assertAggregationPurpose() {
    }

    protected void assertSpecifyPurpose() {
    }

    public static class HpSpecification {
        protected List<String> columnList = new ArrayList<>();

            _specification = new HpSpecification();
        }
        return _specification;
    }

    protected void assertQueryPurpose() {
    }

    protected void assertAggregationPurpose() {
    }

    protected void assertSpecifyPurpose() {
    }

    public static class HpSpecification {
        protected List<String> columnList = new ArrayList<>();

    return queryList.toArray(new Element[0]);
  }

  private Set<Element> createData() {
    Set<Element> set = Sets.newHashSetWithExpectedSize(size);
    while (set.size() < size) {
      set.add(newElement());
    }
    return set;
  }

  private Element newElement() {
    int value = random.nextInt();
    return isUserTypeFast ? new Element(value) : new SlowElement(value);
  }