private final ImmutableSortedSet<E> forward;

  DescendingImmutableSortedSet(ImmutableSortedSet<E> forward) {
    super(Ordering.from(forward.comparator()).reverse());
    this.forward = forward;
  }

  @Override
  public boolean contains(@CheckForNull Object object) {
    return forward.contains(object);
  }

  @Override
  public int size() {
    return forward.size();
  }

  @Override

  private final transient ImmutableSortedMultiset<E> forward;

  DescendingImmutableSortedMultiset(ImmutableSortedMultiset<E> forward) {
    this.forward = forward;
  }

  @Override
  public int count(@CheckForNull Object element) {
    return forward.count(element);
  }

  @Override
  @CheckForNull
  public Entry<E> firstEntry() {
    return forward.lastEntry();
  }

  @Override
  @CheckForNull

  private final transient ImmutableSortedMultiset<E> forward;

  DescendingImmutableSortedMultiset(ImmutableSortedMultiset<E> forward) {
    this.forward = forward;
  }

  @Override
  public int count(@CheckForNull Object element) {
    return forward.count(element);
  }

  @Override
  @CheckForNull
  public Entry<E> firstEntry() {
    return forward.lastEntry();
  }

  @Override
  @CheckForNull

  private final ImmutableSortedSet<E> forward;

  DescendingImmutableSortedSet(ImmutableSortedSet<E> forward) {
    super(Ordering.from(forward.comparator()).reverse());
    this.forward = forward;
  }

  @Override
  public boolean contains(@CheckForNull Object object) {
    return forward.contains(object);
  }

  @Override
  public int size() {
    return forward.size();
  }

  @Override

namespace gradients {
namespace {

class ReluGradientFunction : public GradientFunction {
 public:
  explicit ReluGradientFunction(vector<AbstractTensorHandle*> f_outputs)
      : forward_outputs_(f_outputs) {
    for (auto output : forward_outputs_) {
      if (output) {
        output->Ref();
      }
    }
  }

  Status Compute(AbstractContext* ctx,
                 absl::Span<AbstractTensorHandle* const> grad_outputs,

    BiMapPair<K, V> copy = SerializableTester.reserialize(pair);
    assertEquals(pair.forward, copy.forward);
    assertEquals(pair.backward, copy.backward);
    assertSame(copy.backward, copy.forward.inverse());
    assertSame(copy.forward, copy.backward.inverse());
  }

  private static class BiMapPair<K, V> implements Serializable {
    final BiMap<K, V> forward;
    final BiMap<V, K> backward;

    BiMapPair(BiMap<K, V> original) {

    BiMapPair<K, V> copy = SerializableTester.reserialize(pair);
    assertEquals(pair.forward, copy.forward);
    assertEquals(pair.backward, copy.backward);
    assertSame(copy.backward, copy.forward.inverse());
    assertSame(copy.forward, copy.backward.inverse());
  }

  private static class BiMapPair<K, V> implements Serializable {
    final BiMap<K, V> forward;
    final BiMap<V, K> backward;

    BiMapPair(BiMap<K, V> original) {

 * the <a href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p><b>Warning:</b> The methods of {@code ForwardingSortedMultiset} forward
 * <b>indiscriminately</b> to the methods of the delegate. For example, overriding {@link
 * #add(Object, int)} alone <b>will not</b> change the behavior of {@link #add(Object)}, which can

 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p><b>Warning:</b> The methods of {@code ForwardingMapEntry} forward <i>indiscriminately</i> to
 * the methods of the delegate. For example, overriding {@link #getValue} alone <i>will not</i>
 * change the behavior of {@link #equals}, which can lead to unexpected behavior. In this case, you

      ASSERT_NEAR(manuals[j], danalytical[j], abs_error);
    }
  }

  TF_DeleteTensor(analytical_tensor);
  delete[] danalytical;
}

Model BuildGradModel(Model forward, GradientRegistry registry) {
  return [forward_model = std::move(forward),
          grad_registry = std::move(registry)](
             AbstractContext* ctx,
             absl::Span<AbstractTensorHandle* const> inputs,