assertTrue(future.isDone());
    assertTrue(future.isCancelled());
  }

  public void testAwaitClear() {
    WeakReference<Object> ref = new WeakReference<>(new Object());
    GcFinalization.awaitClear(ref);
    assertNull(ref.get());
  }

  public void testAwaitDone_finalizationPredicate() {
    WeakHashMap<Object, Object> map = new WeakHashMap<>();
    map.put(new Object(), Boolean.TRUE);

  public void testWeakImplementations() {
    for (Striped<?> striped : weakImplementations()) {
      WeakReference<Object> weakRef = new WeakReference<>(striped.get(new Object()));
      GcFinalization.awaitClear(weakRef);
    }
  }

  @AndroidIncompatible // Presumably GC doesn't trigger, despite our efforts.
  public void testWeakReadWrite() {
    Striped<ReadWriteLock> striped = Striped.lazyWeakReadWriteLock(1000);

  public void testWeakImplementations() {
    for (Striped<?> striped : weakImplementations()) {
      WeakReference<Object> weakRef = new WeakReference<>(striped.get(new Object()));
      GcFinalization.awaitClear(weakRef);
    }
  }

  @AndroidIncompatible // Presumably GC doesn't trigger, despite our efforts.
  public void testWeakReadWrite() {
    Striped<ReadWriteLock> striped = Striped.lazyWeakReadWriteLock(1000);

    assertTrue(future.isDone());
    assertTrue(future.isCancelled());
  }

  public void testAwaitClear() {
    WeakReference<Object> ref = new WeakReference<>(new Object());
    GcFinalization.awaitClear(ref);
    assertNull(ref.get());
  }

  public void testAwaitDone_finalizationPredicate() {
    WeakHashMap<Object, Object> map = new WeakHashMap<>();
    map.put(new Object(), Boolean.TRUE);

          @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(Object object) {
    return new Callable<String>() {
      @Override
      public String call() {
        return object.toString();
      }

   */
  private WeakReference<ReferenceQueue<Object>> queueReference;

  @Test
  public void testThatFinalizerStops() {
    weaklyReferenceQueue();
    GcFinalization.awaitClear(queueReference);
  }

  /** If we don't keep a strong reference to the reference object, it won't be enqueued. */
  @Nullable FinalizableWeakReference<Object> reference;

   */
  private WeakReference<ReferenceQueue<Object>> queueReference;

  @Test
  public void testThatFinalizerStops() {
    weaklyReferenceQueue();
    GcFinalization.awaitClear(queueReference);
  }

  /** If we don't keep a strong reference to the reference object, it won't be enqueued. */
  @Nullable FinalizableWeakReference<Object> reference;