code: def test_innovations_nonstationary(ar_params):
      np.random.seed(42)
      endog = np.random.normal(size=100)
      with pytest.raises(
          ValueError, match="The model's autoregressive"
      ):
          arma_innovations.arma_innovations(endog, ar_params=ar_params)
  
imports: import numpy
  import pytest
  from numpy.testing import assert_allclose
  from statsmodels.tsa.innovations import arma_innovations
  from statsmodels.tsa.statespace.sarimax import SARIMAX
label_desc: Use image node_id 2 for calling a global function with example usage: test_innovations_nonstationary(ar_params) without return types