code: def setUp(self):
      self.game = BayesianNetwork(
          [
              ("A", "X"),
              ("A", "B"),
              ("C", "B"),
              ("C", "Y"),
              ("X", "Y"),
              ("B", "X"),
          ]
      )
      self.inference = CausalInference(self.game)
  
      self.dag_bd1 = BayesianNetwork(
          [("X", "Y"), ("Z1", "X"), ("Z1", "Y")]
      )
      self.inference_bd = CausalInference(self.dag_bd1)
  
      self.dag_bd2 = BayesianNetwork(
          [("X", "Y"), ("Z1", "X"), ("Z1", "Z2"), ("Z2", "Y")]
      )
      self.inference_bd2 = CausalInference(self.dag_bd2)
  
imports: import unittest
  import numpy
  import numpy.testing
  import pandas
  from pgmpy.factors.discrete import TabularCPD
  from pgmpy.inference.CausalInference import CausalInference
  from pgmpy.models import BayesianNetwork
label_desc: Use image node_id 1 for calling the TestCausalGraphMethods obj's underlying member method code with example usage: obj.setUp() without return types