private final Entry<K, V> delegate;
    private final Object mutex;

    TestEntry(Entry<K, V> delegate, Object mutex) {
      this.delegate = delegate;
      this.mutex = mutex;
    }

    @Override
    protected Entry<K, V> delegate() {
      return delegate;
    }

    @Override
    public boolean equals(@Nullable Object object) {

  @Override
  protected abstract Deque<E> delegate();

  @Override
  public void addFirst(@ParametricNullness E e) {
    delegate().addFirst(e);
  }

  @Override
  public void addLast(@ParametricNullness E e) {
    delegate().addLast(e);
  }

  @Override
  public Iterator<E> descendingIterator() {
    return delegate().descendingIterator();
  }

  @Override
  @ParametricNullness

    private final Queue<E> delegate = Lists.newLinkedList();
    public final Object mutex = new Object[0]; // something Serializable

    @Override
    public boolean offer(E o) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.offer(o);
    }

    @Override
    public @Nullable E poll() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.poll();
    }

    @Override

  public EqualsTester testEquals() {
    RelationshipTester<Object> delegate =
        new RelationshipTester<>(
            Equivalence.equals(), "Object#equals", "Object#hashCode", itemReporter);
    for (List<Object> group : equalityGroups) {
      delegate.addRelatedGroup(group);
    }
    for (int run = 0; run < REPETITIONS; run++) {
      testItems();
      delegate.test();
    }
    return this;
  }

    protected Object delegate;

    public BaseObject() {}

    public BaseObject(Object delegate, BaseObject parent) {
        this.delegate = requireNonNull(delegate, "delegate cannot be null");
        this.childrenTracking = parent != null ? parent::replace : null;
    }

    public BaseObject(Object delegate, ChildrenTracking parent) {
        this.delegate = requireNonNull(delegate, "delegate cannot be null");

    protected Object delegate;

    public BaseObject() {}

    public BaseObject(Object delegate, BaseObject parent) {
        this.delegate = requireNonNull(delegate, "delegate cannot be null");
        this.childrenTracking = parent != null ? parent::replace : null;
    }

    public BaseObject(Object delegate, ChildrenTracking parent) {
        this.delegate = requireNonNull(delegate, "delegate cannot be null");

          @Override
          public NoDelegateToEquals apply(Equals delegate) {
            return new NoDelegateToEquals(delegate);
          }
        };

    private final Equals delegate;

    NoDelegateToEquals(Equals delegate) {
      this.delegate = delegate;
    }

    @Override
    public String toString() {
      return delegate.toString();
    }
  }

    assertThat(future.setFuture(delegate)).isTrue();
    assertThat(future.cancel(true /* mayInterruptIfRunning */)).isTrue();
    assertCancelled(future, true);
    assertCancelled(delegate, true);
  }

  public void testSetFutureDelegateAlreadySuccessful() throws Exception {
    delegate.set(5);
    assertThat(future.setFuture(delegate)).isTrue();
    assertSuccessful(future, 5);
  }

  @Override
  protected abstract BlockingDeque<E> delegate();

  @Override
  public int remainingCapacity() {
    return delegate().remainingCapacity();
  }

  @Override
  public void putFirst(E e) throws InterruptedException {
    delegate().putFirst(e);
  }

  @Override
  public void putLast(E e) throws InterruptedException {
    delegate().putLast(e);
  }

  @Override

  /**
   * An SSL socket factory that forwards all calls to a delegate. Override {@link #configureSocket}
   * to customize a created socket before it is returned.
   */
  static class DelegatingSSLSocketFactory extends SSLSocketFactory {
    protected final SSLSocketFactory delegate;

    DelegatingSSLSocketFactory(SSLSocketFactory delegate) {
      this.delegate = delegate;
    }