mutex_lock l(graph->mu);
  tensorflow::shape_inference::InferenceContext* ic =
      graph->refiner.GetContext(node);
  if (ic == nullptr) {
    status->status =
        InvalidArgument("Node ", node->name(), " was not found in the graph");
    return;
  }

  auto shape_and_type_vec =
      std::vector<tensorflow::shape_inference::ShapeAndType>(
          num_shapes_and_types);
  for (int i = 0; i < num_shapes_and_types; ++i) {

    TF_RETURN_IF_ERROR(operation->Execute(
        absl::Span<AbstractTensorHandle*>(outputs), &num_outputs));

    if (num_outputs != 1) {
      return errors::Internal("Expected 1 output but found ", num_outputs);
    }
    auto* t = dyn_cast<GraphTensor>(outputs[0]);
    if (!t) {
      return tensorflow::errors::InvalidArgument(
          "Unable to cast input to GraphTensor");
    }

  // Validate GraphDef is what we expect.
  bool found_placeholder = false;
  bool found_scalar_const = false;
  bool found_add = false;
  for (const auto& n : graph_def.node()) {
    if (IsPlaceholder(n)) {
      EXPECT_FALSE(found_placeholder);
      found_placeholder = true;
    } else if (IsScalarConst(n, 3)) {
      EXPECT_FALSE(found_scalar_const);
      found_scalar_const = true;
    } else if (IsAddN(n, 2)) {