Method GradientTape

tensorflow/python/eager/pywrap_tfe_src.cc:1230–1233

                                             PyTapeTensor> {
 public:
  explicit GradientTape(bool persistent, bool watch_accessed_variables)
      : tensorflow::eager::GradientTape<PyObject, PyBackwardFunction,
                                        PyTapeTensor>(persistent),
        watch_accessed_variables_(watch_accessed_variables) {}

  virtual ~GradientTape() {
    for (const IdAndVariable& v : watched_variables_) {