code: def test_sarimax_pickle():
      mod = sarimax.SARIMAX(
          macrodata["realgdp"].values, order=(4, 1, 0)
      )
      pkl_mod = pickle.loads(pickle.dumps(mod))
  
      res = mod.smooth(mod.start_params)
      pkl_res = pkl_mod.smooth(mod.start_params)
  
      assert_allclose(res.params, pkl_res.params)
      assert_allclose(res.bse, pkl_res.bse)
      assert_allclose(res.llf, pkl_res.llf)
  
file_path: statsmodels/statsmodels/tsa/statespace/tests/test_save.py
imports: import pickle
  import os
  import tempfile
  import pytest
  from statsmodels import datasets
  from statsmodels.tsa.statespace import sarimax, structural, varmax, dynamic_factor
  from numpy.testing import assert_allclose
label_desc: Use image node_id 4 for calling a global function with example usage: test_sarimax_pickle() without return types