ListenableFuture<?> ignored = serializer.submitAsync(() -> settableFuture, directExecutor());
    serializer.submit(toStringCallable(toBeGCed), directExecutor()).cancel(true);
    toBeGCed = null;
    GcFinalization.awaitClear(ref);
  }

  private static Callable<String> toStringCallable(Object object) {
    return object::toString;
  }

  public void testCancellationDuringReentrancy() throws Exception {

  public void testGetChecked_classUnloading() throws Exception {
    WeakReference<?> classUsedByGetChecked = doTestClassUnloading();
    GcFinalization.awaitClear(classUsedByGetChecked);
  }

  /**
   * Loads {@link WillBeUnloadedException} in a separate {@code ClassLoader}, calls {@code

    ListenableFuture<?> ignored = serializer.submitAsync(() -> settableFuture, directExecutor());
    serializer.submit(toStringCallable(toBeGCed), directExecutor()).cancel(true);
    toBeGCed = null;
    GcFinalization.awaitClear(ref);
  }

  private static Callable<String> toStringCallable(Object object) {
    return object::toString;
  }

  public void testCancellationDuringReentrancy() throws Exception {

  public void testGetChecked_classUnloading() throws Exception {
    WeakReference<?> classUsedByGetChecked = doTestClassUnloading();
    GcFinalization.awaitClear(classUsedByGetChecked);
  }

  /**
   * Loads {@link WillBeUnloadedException} in a separate {@code ClassLoader}, calls {@code

     * the futures are released once the combiner is done running. But we happen to provide this
     * earlier cleanup at the moment, so we're testing it.
     */
    GcFinalization.awaitClear(future1Ref);
    GcFinalization.awaitClear(future2Ref);
  }

  @J2ktIncompatible
  @GwtIncompatible
  public void testWhenAllComplete_releasesInputFuturesUponCancellation() throws Exception {

     * the futures are released once the combiner is done running. But we happen to provide this
     * earlier cleanup at the moment, so we're testing it.
     */
    GcFinalization.awaitClear(future1Ref);
    GcFinalization.awaitClear(future2Ref);
  }

  @J2ktIncompatible
  @GwtIncompatible
  public void testWhenAllComplete_releasesInputFuturesUponCancellation() throws Exception {