code: def test_glm_unknown_link_func():
      class ValidPowerLink(sm.families.links.Power):
          pass
  
      estimator = utils.StatsmodelsSklearnLikeWrapper(
          sm.GLM,
          dict(
              init=dict(family=sm.families.Tweedie(ValidPowerLink(2))),
              fit=dict(maxiter=1),
          ),
      )
      estimator = estimator.fit([[1], [2]], [0.1, 0.2])
  
      assembler = assemblers.StatsmodelsModelAssemblerSelector(
          estimator
      )
  
      with pytest.raises(
          ValueError, match="Unsupported link function 'ValidPowerLink'"
      ):
          assembler.assemble()
  
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 18 for calling a global function with example usage: test_glm_unknown_link_func() without return types