@RetainedLocalRef List<@Nullable Present<V>> localValues = values;
    if (localValues != null) {
      set(combine(localValues));
    }
  }

  @Override
  void releaseResources(ReleaseResourcesReason reason) {
    super.releaseResources(reason);
    this.values = null;
  }

  abstract C combine(List<@Nullable Present<V>> values);

  /** Used for {@link Futures#allAsList} and {@link Futures#successfulAsList}. */

  protected final void afterDone() {
    super.afterDone();

    @RetainedLocalRef ImmutableCollection<? extends Future<?>> localFutures = futures;
    releaseResources(OUTPUT_FUTURE_DONE); // nulls out `futures`

    if (isCancelled() & localFutures != null) {
      boolean wasInterrupted = wasInterrupted();
      for (Future<?> future : localFutures) {