for (auto branch : branches) {
    auto new_retvals =
        llvm::to_vector<4>(branch.front().getTerminator()->getOperands());
    new_retvals.resize(new_retvals.size() + resource_arg_to_new_output.size());
    for (const auto& entry : resource_arg_to_new_output) {
      int64_t resource_arg_index = entry.getFirst();
      int64_t output_index = entry.getSecond();
      new_retvals[output_index] = branch.getArgument(resource_arg_index);

                                  strlen(ResourceHandle::ANONYMOUS_NAME)));

  AbstractTensorHandle* var_handle = nullptr;
  int num_retvals = 1;
  TF_RETURN_IF_ERROR(varhandle_op->Execute(
      absl::MakeSpan(&var_handle, num_retvals), &num_retvals));
  AbstractTensorHandlePtr owned_var_handle(var_handle);
  if (!tensorflow::isa<ImmediateExecutionTensorHandle>(
          owned_var_handle.get())) {

  ArgView output_arg = op_.OnlyOutput();
  Statement("int num_retvals = $0.size()", output_arg.VariableName());
  Statement("return " + Call(op_.VariableName(), "Execute",
                             {output_arg.VariableName(), "&num_retvals"}));
}

void OpImplementationRenderer::RenderExecutionSingleOutput() {
  ArgView output_arg = op_.OnlyOutput();
  Statement("int num_retvals = 1");

  }
  if (TF_GetCode(status) != TF_OK) return nullptr;
  TFE_TensorHandle* var_handle = nullptr;
  int num_retvals = 1;
  TFE_Execute(op, &var_handle, &num_retvals, status);
  if (TF_GetCode(status) != TF_OK) return nullptr;
  TFE_DeleteOp(op);
  if (TF_GetCode(status) != TF_OK) return nullptr;
  CHECK_EQ(1, num_retvals);

  // Assign 'value' to it.
  op = TFE_NewOp(ctx, "AssignVariableOp", status);

  // TODO(bmzhao): Finish API on FunctionMetadata args, so we know how many
  // inputs + outputs a function has.
  TFE_TensorHandle* compute_fn_outputs[1] = {nullptr};
  int num_retvals = 1;

  TFE_Execute(compute_fn_op, &compute_fn_outputs[0], &num_retvals, status);
  EXPECT_EQ(TF_GetCode(status), TF_OK) << TF_Message(status);

  TF_Tensor* result = TFE_TensorHandleResolve(compute_fn_outputs[0], status);

    ASSERT_EQ(TF_GetCode(status), TF_OK) << TF_Message(status);
  }

  TFE_TensorHandle* retvals[1] = {nullptr};
  int num_retvals = 1;
  TFE_Execute(func, &retvals[0], &num_retvals, status);
  EXPECT_EQ(TF_GetCode(status), TF_OK) << TF_Message(status);
  ASSERT_EQ(1, num_retvals);
  TFE_DeleteOp(func);
  TFE_DeleteTensorHandle(packed_handle);
  TF_Tensor* t = TFE_TensorHandleResolve(retvals[0], status);

AbstractOperation* TapeOperation::GetBackingOperation() { return parent_op_; }
Status TapeOperation::Execute(absl::Span<AbstractTensorHandle*> retvals,
                              int* num_retvals) {
  TF_RETURN_IF_ERROR(parent_op_->Execute(retvals, num_retvals));
  for (int i = 0; i < *num_retvals; i++) {
    // TODO(srbs): Manage refcount of ForwardOperation's inputs/outputs.
    forward_op_.outputs.push_back(retvals[i]);
  }

                       NodeDef* call_def) {
  Graph* graph = graph_ptr->get();
  const int num_args = input_permutation->size();
  const int num_retvals = output_permutation->size();

  std::vector<Node*> args;
  std::vector<Node*> retvals;
  args.reserve(num_args);
  retvals.reserve(num_retvals);
  for (Node* n : graph->nodes()) {
    if (n->type_string() == "_Arg") {
      // Check if this is a guaranteed constant.

  ASSERT_EQ(errors::OK, s.code()) << s.message();
  int num_retvals = 1;
  std::vector<AbstractTensorHandle*> outputs(1);
  GradientRegistry registry;
  s = RegisterGradients(&registry);
  ASSERT_EQ(errors::OK, s.code()) << s.message();
  auto tape = std::make_unique<Tape>(/*persistent=*/false);
  s = Execute(check_numerics_op.get(), ctx.get(), absl::MakeSpan(outputs),
              &num_retvals, &forward_op, tape.get(), registry);

                 int* num_retvals) override {
    auto* tf_opdesc = op_.release();
    if (tf_opdesc == nullptr) {
      return errors::InvalidArgument("AbstractOp is incomplete.");
    }
    TF_Status* s = TF_NewStatus();
    auto* operation = TF_FinishOperation(tf_opdesc, s);
    TF_RETURN_IF_ERROR(StatusFromTF_Status(s));
    TF_DeleteStatus(s);
    *num_retvals = TF_OperationNumOutputs(operation);