@Override
          public Object computeNext() {
            return new Object();
          }
        };
    WeakReference<Object> ref = new WeakReference<>(itr.next());
    GcFinalization.awaitClear(ref);
  }

  public void testDefaultBehaviorOfPeekForEmptyIteration() {

    AbstractIterator<Integer> empty =
        new AbstractIterator<Integer>() {
          private boolean alreadyCalledEndOfData;

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

  // Create a second ClassLoader and use it to get a second version of the TestEnum class.
  // Run Enums.getIfPresent on that other TestEnum and then return a WeakReference containing the

          @Override
          public Object computeNext() {
            return new Object();
          }
        };
    WeakReference<Object> ref = new WeakReference<>(itr.next());
    GcFinalization.awaitClear(ref);
  }

  public void testDefaultBehaviorOfPeekForEmptyIteration() {

    AbstractIterator<Integer> empty =
        new AbstractIterator<Integer>() {
          private boolean alreadyCalledEndOfData;

              }
            },
            directExecutor());
    serializer.submit(toStringCallable(toBeGCed), directExecutor()).cancel(true);
    toBeGCed = null;
    GcFinalization.awaitClear(ref);
  }

  private static Callable<String> toStringCallable(final Object object) {
    return new Callable<String>() {
      @Override
      public String call() {
        return object.toString();

              }
            },
            directExecutor());
    serializer.submit(toStringCallable(toBeGCed), directExecutor()).cancel(true);
    toBeGCed = null;
    GcFinalization.awaitClear(ref);
  }

  private static Callable<String> toStringCallable(final Object object) {
    return new Callable<String>() {
      @Override
      public String call() {
        return object.toString();

  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);
  }

  @AndroidIncompatible
  @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);
  }

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