code: def test_pickle_config():
      cfg = Config()
      cfg.register_option("a.b.c", 1)
      cfg.redirect_option("a.c", "a.b.c")
  
      s = pickle.dumps(cfg)
      new_cfg = pickle.loads(s)
      assert new_cfg.a.b.c == 1
      assert new_cfg.a.c == 1
  
file_path: mars/mars/tests/test_config.py
imports: import pickle
  import threading
  import pytest
  from ..config import options, option_context, is_integer, is_string, Config
label_desc: Use image node_id 4 for calling a global function with example usage: test_pickle_config() without return types