class LowerClusterToRuntimeOpsTest : public ::testing::Test {
 public:
  LowerClusterToRuntimeOpsTest() {
    mlir::RegisterCommonToolingDialects(registry_);
    context_.appendDialectRegistry(registry_);
    context_.loadAllAvailableDialects();

    env_ = Env::Default();
    test_group_name_ = "TestGroup";
    test_dir_ = testing::TmpDir();

    ASSERT_EQ(errors::OK, status_.code()) << status_.message();
    x2.reset(x2_raw);
  }

  status_ = registry_.Register("IdentityN", IdentityNRegisterer);
  ASSERT_EQ(errors::OK, status_.code()) << status_.message();
  auto IdentityNGradModel = BuildGradModel(IdentityNModel, registry_);

  std::vector<AbstractTensorHandle*> outputs(2);
  status_ =
      RunModel(IdentityNGradModel, immediate_execution_ctx_.get(),

};

SymbolicGradientBuilder::SymbolicGradientBuilder(
    const Scope& scope, const ops::GradOpRegistry* registry,
    const std::vector<Output>& outputs, const std::vector<Output>& inputs,
    const std::vector<Output>& grad_inputs, std::vector<Output>* grad_outputs)
    : scope_(scope),
      registry_(registry),
      outputs_(outputs),
      inputs_(inputs),
      grad_inputs_(grad_inputs),

Status GradientRegistry::Register(
    const string& op_name, GradientFunctionFactory gradient_function_factory) {
  auto iter = registry_.find(op_name);
  if (iter != registry_.end()) {
    const string error_msg = "Gradient already exists for op: " + op_name + ".";
    return errors::AlreadyExists(error_msg);
  }
  registry_.insert({op_name, gradient_function_factory});
  return absl::OkStatus();
}
Status GradientRegistry::Lookup(

namespace tensorflow {
namespace gradients {
TapeOperation::TapeOperation(AbstractOperation* parent_op, Tape* tape,
                             const GradientRegistry& registry)
    : AbstractOperation(kTape),
      parent_op_(parent_op),
      tape_(tape),
      registry_(registry) {
  // TODO(b/172003047): Consider making AbstractOperation RefCounted.
  // parent_op_->Ref();
}
void TapeOperation::Release() {

	}
}

// Registry is a collection of all available plugins. The framework uses a
// registry to enable and initialize configured plugins.
// All plugins must be in the registry before initializing the framework.
type Registry map[string]PluginFactory

// Register adds a new plugin to the registry. If a plugin with the same name
// exists, it returns an error.

	"k8s.io/kubernetes/pkg/scheduler/framework/runtime"
)

// NewInTreeRegistry builds the registry with all the in-tree plugins.
// A scheduler that runs out of tree plugins can register additional plugins
// through the WithFrameworkOutOfTreeRegistry option.
func NewInTreeRegistry() runtime.Registry {
	fts := plfeature.Features{

	"github.com/google/go-containerregistry/pkg/v1/remote"
	"github.com/google/go-containerregistry/pkg/v1/remote/transport"
)

// Exists returns true if the image in the argument exists in a container registry.
// The argument must be a complete image name, e.g. "gcr.io/istio-release/pilot:1.20.0".
// If the image does not exist, it returns false and an optional error message, for debug purposes.
func Exists(image string) (bool, error) {

	}
	registry1 := serviceregistry.Simple{
		ProviderID:          provider.ID("mockAdapter1"),
		DiscoveryController: discovery1,
	}

	registry2 := serviceregistry.Simple{
		ProviderID:          provider.ID("mockAdapter2"),
		DiscoveryController: discovery2,
	}

	ctls := NewController(Options{&mockMeshConfigHolder{}})
	ctls.AddRegistry(registry1)
	ctls.AddRegistry(registry2)

	return ctls

func isRegistryEqual(registryX, registryY Registry) bool {
	for name, pluginFactory := range registryY {
		if val, ok := registryX[name]; ok {
			p1, _ := pluginFactory(nil, nil, nil)
			p2, _ := val(nil, nil, nil)
			if p1.Name() != p2.Name() {
				// pluginFactory functions are not the same.
				return false
			}
		} else {
			// registryY contains an entry that is not present in registryX