* MoreObjects.toStringHelper(this)
   *     .omitNullValues()
   *     .add("x", 1)
   *     .add("y", null)
   *     .toString();
   * }
   *
   * <p>Note that in GWT, class names are often obfuscated.
   *
   * @param self the object to generate the string for (typically {@code this}), used only for its
   *     class name
   * @since 18.0 (since 2.0 as {@code Objects.toStringHelper()}).
   */

   * MoreObjects.toStringHelper(this)
   *     .omitNullValues()
   *     .add("x", 1)
   *     .add("y", null)
   *     .toString();
   * }
   *
   * <p>Note that in GWT, class names are often obfuscated.
   *
   * @param self the object to generate the string for (typically {@code this}), used only for its
   *     class name
   * @since 18.0 (since 2.0 as {@code Objects.toStringHelper()}).
   */

   * @throws NullPointerException if {@code elements} is null
   */
  @Override
  boolean containsAll(Collection<?> elements);

  /**
   * {@inheritDoc}
   *
   * <p><b>Note:</b> This method ignores how often any element might appear in {@code c}, and only
   * cares whether or not an element appears at all. If you wish to remove one occurrence in this

   * @throws NullPointerException if {@code elements} is null
   */
  @Override
  boolean containsAll(Collection<?> elements);

  /**
   * {@inheritDoc}
   *
   * <p><b>Note:</b> This method ignores how often any element might appear in {@code c}, and only
   * cares whether or not an element appears at all. If you wish to remove one occurrence in this

 * iterators that don't support {@code remove()}. Otherwise, all optional operations are supported.
 * Null row keys, columns keys, and values are not supported.
 *
 * <p>Lookups by row key are often faster than lookups by column key, because the data is stored in
 * a {@code Map<R, Map<C, V>>}. A method call like {@code column(columnKey).get(rowKey)} still runs

 * iterators that don't support {@code remove()}. Otherwise, all optional operations are supported.
 * Null row keys, columns keys, and values are not supported.
 *
 * <p>Lookups by row key are often faster than lookups by column key, because the data is stored in
 * a {@code Map<R, Map<C, V>>}. A method call like {@code column(columnKey).get(rowKey)} still runs

   * scattered in memory and thus don't interfere much with each
   * other. But Atomic objects residing in arrays will tend to be
   * placed adjacent to each other, and so will most often share
   * cache lines (with a huge negative performance impact) without
   * this precaution.
   *
   * In part because Cells are relatively large, we avoid creating

 * }
 *
 * <h3>Alternatives</h3>
 *
 * <h4>Frameworks</h4>
 *
 * <p>When chaining together a graph of asynchronous operations, you will often find it easier to
 * use a framework. Frameworks automate the process, often adding features like monitoring,
 * debugging, and cancellation. Examples of frameworks include:
 *
 * <ul>
 *   <li><a href="https://dagger.dev/producers.html">Dagger Producers</a>

  }

  /**
   * Clears fields that are no longer needed after this future has completed -- or at least all its
   * inputs have completed (more precisely, after {@link #handleAllCompleted()} has been called).
   * Often called multiple times (that is, both when the inputs complete and when the output
   * completes).
   *
   * <p>This is similar to our proposed {@code afterCommit} method but not quite the same. See the

    if ((!features.contains(IteratorFeature.SUPPORTS_REMOVE) && removes > 1)
        || (stimuli.length >= 5 && removes > 2)) {
      // removes are the most expensive thing to test, since they often throw exceptions with stack
      // traces, so we test them a bit less aggressively
      return;
    }

    MultiExceptionListIterator reference = new MultiExceptionListIterator(expectedElements);