code: def tearDown(self):
      get_reusable_executor().shutdown(wait=True)
  
imports: import unittest
  import networkx
  import numpy
  import pandas
  from joblib.externals.loky import get_reusable_executor
  from pgmpy.estimators import PC
  from pgmpy.independencies import Independencies
  from pgmpy.models import BayesianNetwork
  from pgmpy.sampling import BayesianModelSampling
  from pgmpy.utils import get_example_model
label_desc: Use image node_id 4 for calling the TestPCEstimatorFromIndependencies obj's underlying member method code with example usage: obj.tearDown() without return types