const ParallelDevice& device_;
  std::vector<TensorHandlePtr> tensors_;
  // Parallel tensors are immutable but compute their shape lazily unless it is
  // provided on construction. The optional has a value if the lazy computation
  // has been completed or the shape was provided on construction.
  mutable absl::optional<std::vector<int64_t>> shape_;
  const TF_DataType dtype_;
};

template <typename DataType>

// In either case, it deletes `desc`.
TF_CAPI_EXPORT extern TF_Operation* TF_FinishOperation(
    TF_OperationDescription* desc, TF_Status* status);

// TF_Operation functions.  Operations are immutable once created, so
// these are all query functions.

TF_CAPI_EXPORT extern const char* TF_OperationName(TF_Operation* oper);
TF_CAPI_EXPORT extern const char* TF_OperationOpType(TF_Operation* oper);

};

struct TF_DeprecatedSession {
  tensorflow::Session* session;
};

struct TF_Library {
  void* lib_handle;
  TF_Buffer op_list;
};

struct TF_Graph {
  TF_Graph();

  mutable tensorflow::mutex mu;
  tensorflow::Graph graph TF_GUARDED_BY(mu);

  // Runs shape inference.
  tensorflow::ShapeRefiner refiner TF_GUARDED_BY(mu);

  // Maps from name of an operation to the Node* in 'graph'.