namespace tensorflow {

Operation::Operation(Node* n) : inputs_(GetInputs(n)), node_(n) {}

Output Operation::input(int32_t i) const {
  CHECK_NOTNULL(node_);
  CHECK_GE(i, 0);
  CHECK_LT(i, node_->num_inputs());
  // Handle the case where the input was unknown at the time this
  // Operation was constructed.
  if (inputs_[i].first == nullptr && inputs_[i].second == -1) {

  handle_data.set_is_set(true);
  {
    mutex_lock l(graph->mu);
    tensorflow::shape_inference::InferenceContext* ic =
        graph->refiner.GetContext(node);
    CHECK(ic != nullptr);
    CHECK_LT(output.index, ic->num_outputs());
    const auto* shapes_and_types =
        ic->output_handle_shapes_and_types(output.index);
    if (shapes_and_types == nullptr) return "";

    for (const auto& p : *shapes_and_types) {

}

TF_DataType TF_InputDatatype(TF_OpKernelContext* ctx, int index) {
  auto* cc_ctx = reinterpret_cast<::tensorflow::OpKernelContext*>(ctx);
  CHECK_GE(index, 0);                     // Crash OK
  CHECK_LT(index, cc_ctx->num_inputs());  // Crash OK
  return static_cast<TF_DataType>(cc_ctx->input_dtype(index));
}

void TF_SetOutput(TF_OpKernelContext* ctx, int i, const TF_Tensor* tensor,

    const XlaCompiler::ResourceUpdate& write =
        compilation_result->resource_updates[i];
    int actual_input_index = write.input_index - missing_ctx_input_prefix;
    CHECK_GE(actual_input_index, 0);
    CHECK_LT(actual_input_index, ctx->num_inputs());
    Var* var = variable_infos[variable_info_lookup[actual_input_index]].var();
    CHECK(var);

    VLOG(2) << "Updating variable #" << i

    tensors_.push_back(device_tensor);
    return device_tensor;
  }

  // Gets the `output_index`-th output set in the context_
  Tensor* GetOutput(int output_index) {
    CHECK_LT(output_index, context_->num_outputs());
    Tensor* device_tensor = context_->mutable_output(output_index);
    managed_outputs_.resize(context_->num_outputs());
    if (managed_outputs_[output_index]) {

  {
    mutex_lock l(graph->mu);
    tensorflow::shape_inference::InferenceContext* ic =
        graph->refiner.GetContext(node);
    CHECK(ic != nullptr);                       // Crash OK
    CHECK_LT(output.index, ic->num_outputs());  // Crash OK
    const auto* shapes_and_types =
        ic->output_handle_shapes_and_types(output.index);
    if (shapes_and_types == nullptr) return nullptr;