*   WeakReference<Foo> weakRef = new WeakReference<>(x);
 *   // ... use x ...
 *   x = null;  // Hint to the JIT that x is stack-unreachable
 *   return weakRef;
 * }
 * public void testFooLeak() {
 *   GcFinalization.awaitClear(fooWeakRef());
 * }
 * }
 *
 * <p>This class cannot currently be used to test soft references, since this class does not try to
 * create the memory pressure required to cause soft references to be cleared.
 *

    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);

 *   WeakReference<Foo> weakRef = new WeakReference<>(x);
 *   // ... use x ...
 *   x = null;  // Hint to the JIT that x is stack-unreachable
 *   return weakRef;
 * }
 * public void testFooLeak() {
 *   GcFinalization.awaitClear(fooWeakRef());
 * }
 * }
 *
 * <p>This class cannot currently be used to test soft references, since this class does not try to
 * create the memory pressure required to cause soft references to be cleared.
 *

    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);

    assertSame(canonical, pool.intern(canonical));

    WeakReference<Integer> signal = new WeakReference<>(canonical);
    canonical = null; // Hint to the JIT that canonical is unreachable

    GcFinalization.awaitClear(signal);
    assertSame(not, pool.intern(not));
  }

  public void testAsFunction_simplistic() {
    String canonical = "a";
    String not = new String("a");

    Function<String, String> internerFunction =

    assertSame(canonical, pool.intern(canonical));

    WeakReference<Integer> signal = new WeakReference<>(canonical);
    canonical = null; // Hint to the JIT that canonical is unreachable

    GcFinalization.awaitClear(signal);
    assertSame(not, pool.intern(not));
  }

  public void testAsFunction_simplistic() {
    String canonical = "a";
    String not = new String("a");

    Function<String, String> internerFunction =

          @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();
      }