code: def tearDown(self):
      del self.model1
      del self.model2
      del self.data1
      del self.data2
  
      get_reusable_executor().shutdown(wait=True)
  
      config.set_backend("numpy")
  
file_path: pgmpy/pgmpy/tests/test_estimators/test_EM.py
imports: import unittest
  import numpy
  import pandas
  from joblib.externals.loky import get_reusable_executor
  from pgmpy import config
  from pgmpy.estimators import ExpectationMaximization
  from pgmpy.models import BayesianNetwork
  from pgmpy.sampling import BayesianModelSampling
  from pgmpy.utils import get_example_model
label_desc: Use image node_id 3 for calling the TestEMTorch obj's underlying member method code with example usage: obj.tearDown() without return types