*     fetchCounters().catching(FetchException.class, x -> 0, directExecutor());
   * }</pre>
   *
   * <p>When selecting an executor, note that {@code directExecutor} is dangerous in some cases. See
   * the discussion in the {@link #addListener} documentation. All its warnings about heavyweight
   * listeners are also applicable to heavyweight functions passed to this method.
   *

@ElementTypesAreNonnullByDefault
abstract class CollectionFuture<V extends @Nullable Object, C extends @Nullable Object>
    extends AggregateFuture<V, C> {
  /*
   * We access this field racily but safely. For discussion of a similar situation, see the comments
   * on the fields of TimeoutFuture. This field is slightly different from the fields discussed

    checkMessage(expected);
  }

  @J2ktIncompatible
  @GwtIncompatible // NullPointerTester
  public void testNullPointers() {
    // Don't bother testing: Verify is like Preconditions. See the discussion on that class.
  }

  private static final Object IGNORE_ME =
      new Object() {
        @Override
        public String toString() {
          throw new AssertionFailedError();
        }
      };

-   [StackOverflow: Ask "how-to" and "why-didn't-it-work" questions](https://stackoverflow.com/questions/ask?tags=guava+java)
-   [guava-discuss: For open-ended questions and discussion](https://groups.google.com/group/guava-discuss)

## IMPORTANT WARNINGS

1. APIs marked with the `@Beta` annotation at the class or method level
are subject to change. They can be modified in any way, or even

    checkMessage(expected);
  }

  @J2ktIncompatible
  @GwtIncompatible // NullPointerTester
  public void testNullPointers() {
    // Don't bother testing: Verify is like Preconditions. See the discussion on that class.
  }

  private static final Object IGNORE_ME =
      new Object() {
        @Override
        public String toString() {
          throw new AssertionFailedError();
        }
      };

///

* Check if there's a <a href="https://github.com/fastapi/fastapi/discussions/categories/translations" class="external-link" target="_blank">GitHub Discussion</a> to coordinate translations for your language. You can subscribe to it, and when there's a new pull request to review, an automatic comment will be added to the discussion.

-   [guava-announce: Announcements of releases and upcoming significant changes](https://groups.google.com/group/guava-announce)
-   [guava-discuss: For open-ended questions and discussion](https://groups.google.com/group/guava-discuss)

## IMPORTANT WARNINGS

1.  APIs marked with the `@Beta` annotation at the class or method level are

   *
   * <p>Cancelling the pipeline will not cancel {@code future}, so that the pipeline can access its
   * value in order to close it.
   *
   * @param future the future to create the {@code ClosingFuture} from. For discussion of the
   *     future's result type {@code C}, see {@link DeferredCloser#eventuallyClose(Object,
   *     Executor)}.
   * @param closingExecutor the future's result will be closed on this executor

  }

  private static final class AboveAll extends Cut<Comparable<?>> {
    private static final AboveAll INSTANCE = new AboveAll();

    private AboveAll() {
      // For discussion of "", see BelowAll.
      super("");
    }

    @Override
    Comparable<?> endpoint() {
      throw new IllegalStateException("range unbounded on this side");
    }

    @Override

      this.left = null;
      this.right = null;
    }

    /** Constructor for the header node. */
    AvlNode() {
      this.elem = null;
      this.elemCount = 1;
    }

    // For discussion of pred() and succ(), see the comment on the pred and succ fields.

    private AvlNode<E> pred() {
      return requireNonNull(pred);
    }

    private AvlNode<E> succ() {
      return requireNonNull(succ);