code: def set_mode(self, mode):
      # raise KeyError
      self.update(MODE_CONF[mode])
  
imports: from __future__ import annotations
  import os
  import re
  import copy
  import logging
  import platform
  import multiprocessing
  from pathlib import Path
  from typing import Callable, Optional, Union
  from typing import TYPE_CHECKING
  from qlib.constant import REG_CN, REG_US, REG_TW
label_desc: Use image node_id 2 for calling the QlibConfig obj's underlying member method code with example usage: obj.set_mode(mode) without return types