code: def _process(self):
      self.__read_gtn_data(self._raw_directory)
      self.__transform_gtn_data()
      torch.save(self.__data, list(self._processed_file_paths)[0])
  
imports: import os
  import os.path
  import shutil
  import pickle
  import numpy
  import torch
  import typing
  from autogl.data import Data, download_url, InMemoryStaticGraphSet
  from autogl.data.graph import GeneralStaticGraphGenerator
  from ._dataset_registry import DatasetUniversalRegistry
  from ._data_source import OnlineDataSource
  from ..None import backend
label_desc: Use image node_id 7 for calling the _GTNDataSource obj's underlying member method code with example usage: obj._process() without return types