code: def _getModelExtraDataDir(saveModelDir):
      
      path = os.path.join(saveModelDir, "modelextradata")
      path = os.path.abspath(path)
  
      return path
docs: Return the absolute path to the directory where the model's own
      "extra data" are stored (i.e., data that's too big for pickling).
  
      :param saveModelDir: (string)
             Directory of where the experiment is to be or was saved
      :returns: (string) An absolute path.