}
        TFE_OpSetAttrTypeList(
            op, attr_name,
            reinterpret_cast<const TF_DataType*>(type_vector.data()),
            type_size);
      }

      // Rest are not supported.
      if (default_value.list().shape_size() > 0 ||
          default_value.list().func_size() > 0 ||
          default_value.list().tensor_size() > 0) {

auto& kUnknownDim = shape_inference::InferenceContext::kUnknownDim;
auto& kUnknownRank = shape_inference::InferenceContext::kUnknownRank;

// GraphTensor wraps a `TF_Output`, i.e. a pointer to TF_Operation and the index
// into the list of outputs for the operation.
class GraphTensor : public TracingTensorHandle {
 public:
  explicit GraphTensor(TF_Output output, TF_Graph* graph)
      : TracingTensorHandle(kGraph), output_(output), graph_(graph) {}