code: def test_glm_unknown_link_func():
      class ValidIdentityLink(linear_model._glm.link.IdentityLink):
          pass
  
      estimator = linear_model.TweedieRegressor(
          power=1, link=ValidIdentityLink(), max_iter=10
      )
      estimator = estimator.fit([[1], [2]], [0.1, 0.2])
  
      assembler = assemblers.SklearnGLMModelAssembler(estimator)
  
      with pytest.raises(
          ValueError,
          match="Unsupported link function 'ValidIdentityLink'",
      ):
          assembler.assemble()
  
file_path: m2cgen/tests/assemblers/test_linear_sklearn.py
imports: import numpy
  import pytest
  from sklearn import linear_model
  from m2cgen import assemblers, ast
  from tests.utils import cmp_exprs
label_desc: Use image node_id 7 for calling a global function with example usage: test_glm_unknown_link_func() without return types