code: def test_unknown_model():
      class ValidGLS(sm.GLS):
          pass
  
      estimator = utils.StatsmodelsSklearnLikeWrapper(ValidGLS, {})
      _, __, estimator = utils.get_regression_model_trainer()(estimator)
  
      with pytest.raises(
          NotImplementedError, match="Model 'ValidGLS' is not supported"
      ):
          assemblers.StatsmodelsModelAssemblerSelector(estimator)
  
imports: import numpy
  import pytest
  import statsmodels.api
  from statsmodels.regression.process_regression import ProcessMLE
  from m2cgen import assemblers, ast
  from tests import utils
label_desc: Use image node_id 4 for calling a global function with example usage: test_unknown_model() without return types