code: def test_brockwell_davis_example_662():
      endog = lake.copy()
      exog = np.c_[
          np.ones_like(endog), np.arange(1, len(endog) + 1) * 1.0
      ]
  
      res, _ = gls(endog, exog, order=(2, 0, 0))
  
      # Parameter values taken from Table 6.3 row 2, except for sigma2 and the
      # last digit of the exog_params[0], which were given in the text
      assert_allclose(res.exog_params, [10.091, -0.0216], atol=1e-3)
      assert_allclose(res.ar_params, [1.005, -0.291], atol=1e-3)
      assert_allclose(res.sigma2, 0.4571, atol=1e-3)
  
file_path: statsmodels/statsmodels/tsa/arima/estimators/tests/test_gls.py
imports: import numpy
  import pytest
  from numpy.testing import assert_, assert_allclose, assert_equal, assert_warns, assert_raises
  from statsmodels.tsa.arima.datasets.brockwell_davis_2002 import lake, oshorts
  from statsmodels.tsa.arima.estimators.gls import gls
label_desc: Use image node_id 2 for calling a global function with example usage: test_brockwell_davis_example_662() without return types