string op_name;
  std::vector<string> arg_types;
  std::vector<string> arg_names;
  std::vector<string> output_types;
  std::vector<string> output_names;
  std::vector<bool> is_list_output;
  bool has_optional_attrs;
  string comment;

  const OpDef& graph_op_def;
  const ApiDef& api_def;
  const std::vector<string>& aliases;