code: def test_make_key():
      class DummyTest:
          def __init__(self, value):
              self.value = value
  
          def dummy_method(
              self, value
          ):  # Add this method to by pass linting
              self.value = value
  
      test = DummyTest(8)
      test.dummy_method(10)
      with pytest.raises(ValueError, match=r"Unexpected type"):
          make_key(test)
  
imports: from __future__ import division
  import copy
  from collections import Counter
  import pytest
  from causalnex.ebaybbn import BBNNode, JoinTree, JoinTreeCliqueNode, SepSet, build_bbn, build_bbn_from_conditionals, build_join_tree, combinations, make_moralized_copy, make_node_func, make_undirected_copy, priority_func, triangulate
  from causalnex.ebaybbn.exceptions import VariableNotInGraphError, VariableValueNotInDomainError
  from causalnex.ebaybbn.graph import Node, UndirectedNode
  from causalnex.ebaybbn.utils import get_args, get_original_factors, make_key
label_desc: Use image node_id 10 for calling a global function with example usage: test_make_key() without return types