}
            delegate = newDelegate;
        }
    }

    protected boolean replace(Object oldDelegate, Object newDelegate) {
        return false;
    }

    @FunctionalInterface
    protected interface ChildrenTracking {
        boolean replace(Object oldDelegate, Object newDelegate);
    }

   */
  protected abstract <T extends @Nullable Object> Callable<T> wrapTask(Callable<T> callable);

  /**
   * Wraps a {@code Runnable} for submission to the underlying executor. The default implementation
   * delegates to {@link #wrapTask(Callable)}.
   */
  protected Runnable wrapTask(Runnable command) {
    Callable<Object> wrapped = wrapTask(callable(command, null));
    return () -> {
      try {

        final List<Map<String, Object>> jobLogList = readJobLog(NAME_PREFIX);
        for (Map<String, Object> elem : jobLogList) {
            deleteMethod(API_PATH + "/log/" + elem.get("id"));
        }
        refresh();

        // Clean up crawling info
        final List<Map<String, Object>> crawlingInfoList = readCrawlingInfo(webConfigId);
        for (Map<String, Object> elem : crawlingInfoList) {

    class Transformer implements Function<Object, Object> {
      @SuppressWarnings("nullness:initialization.field.uninitialized")
      ListenableFuture<Object> output;

      @Override
      public Object apply(Object input) {
        output.cancel(false);
        throw new SomeError();
      }
    }
    Transformer transformer = new Transformer();
    SettableFuture<Object> input = SettableFuture.create();

    class Transformer implements Function<Object, Object> {
      @SuppressWarnings("nullness:initialization.field.uninitialized")
      ListenableFuture<Object> output;

      @Override
      public Object apply(Object input) {
        output.cancel(false);
        throw new SomeError();
      }
    }
    Transformer transformer = new Transformer();
    SettableFuture<Object> input = SettableFuture.create();

 */
@GwtCompatible
abstract class AbstractTable<
        R extends @Nullable Object, C extends @Nullable Object, V extends @Nullable Object>
    implements Table<R, C, V> {

  @Override
  public boolean containsRow(@Nullable Object rowKey) {
    return Maps.safeContainsKey(rowMap(), rowKey);
  }

  @Override
  public boolean containsColumn(@Nullable Object columnKey) {
    return Maps.safeContainsKey(columnMap(), columnKey);
  }

      return false;
    }
  }

  /**
   * A sensible default implementation of {@link #subMap(Object, Object)} in terms of {@link
   * #headMap(Object)} and {@link #tailMap(Object)}. In some situations, you may wish to override
   * {@link #subMap(Object, Object)} to forward to this implementation.
   *
   * @since 7.0
   */
  protected SortedMap<K, V> standardSubMap(K fromKey, K toKey) {

  }

  public void testAwaitClear() {
    WeakReference<Object> ref = createWeakReference();
    GcFinalization.awaitClear(ref);
    assertThat(ref.get()).isNull();
  }

  private WeakReference<Object> createWeakReference() {
    return new WeakReference<>(new Object());
  }

  public void testAwaitDone_finalizationPredicate() {
    WeakHashMap<Object, Object> map = new WeakHashMap<>();

                        "type": "object",
                        "properties": {"name": {"title": "Name", "type": "string"}},
                    },
                    "ValidationError": {
                        "title": "ValidationError",
                        "required": ["loc", "msg", "type"],
                        "type": "object",
                        "properties": {

        return element
    }

    protected Element createNode(Object name, Object value) {
        return createNode(name, [:], value)
    }

    protected void setParent(Object parent, Object child) {
        parent.appendChild(child)
    }

    def appendChild(Node node) {
        if (!current) {
            elements << (Element) document.importNode(node, true)
        } else  {