code: def _reverse_io():
      _in_buf.seek(0)
      _out_buf.seek(0)
      _set_out_file(_in_buf)
      _set_in_file(_out_buf)
  
file_path: nni/test/ut/sdk/test_msg_dispatcher.py
imports: import json
  from io import BytesIO
  from unittest import TestCase, main
  from nni.runtime import msg_dispatcher_base
  from nni.runtime.msg_dispatcher import MsgDispatcher
  from nni.runtime.tuner_command_channel.legacy import *
  from nni.tuner import Tuner
  from nni.utils import extract_scalar_reward
label_desc: Use image node_id 1 for calling a global function with example usage: _reverse_io() without return types