code: def test_unbiased_error():
      # Test that we get the appropriate error when we specify unbiased=True
      # but the second-stage yields non-stationary parameters.
      endog = np.arange(1000) * 1.0
      with pytest.raises(ValueError, match="Cannot perform third step"):
          hannan_rissanen(endog, ar_order=1, ma_order=1, unbiased=True)
  
imports: import numpy
  import pytest
  from numpy.testing import assert_allclose
  from statsmodels.tsa.innovations.arma_innovations import arma_innovations
  from statsmodels.tsa.arima.datasets.brockwell_davis_2002 import lake
  from statsmodels.tsa.arima.estimators.hannan_rissanen import hannan_rissanen, _validate_fixed_params, _package_fixed_and_free_params_info, _stitch_fixed_and_free_params
  from statsmodels.tsa.arima.specification import SARIMAXSpecification
  from statsmodels.tools.tools import Bunch
label_desc: Use image node_id 6 for calling a global function with example usage: test_unbiased_error() without return types