code: def _open_file_or_buffer(file_like, mode):
      if _is_path(file_like):
          return _open_file(file_like, mode)
      else:
          if "w" in mode:
              return _open_buffer_writer(file_like)
          elif "r" in mode:
              return _open_buffer_reader(file_like)
          else:
              invalidInputError(
                  f"Expected 'r' or 'w' in mode but got {mode}"
              )
  
imports: import torch
  from torch.utils.data import Dataset
  import io
  import os
  import pathlib
  from cryptography.fernet import Fernet
  from typing import BinaryIO, Union, IO, Optional
  import pickle
  from bigdl.nano.utils.common import invalidInputError
label_desc: Use image node_id 2 for calling a global function with example usage: _open_file_or_buffer(file_like, mode) and returns: _open_file, _open_buffer_writer, _open_buffer_reader