code: def tearDown(self):
      config.set_backend("numpy")
  
imports: import unittest
  import networkx
  import numpy
  from pgmpy import config
  from pgmpy.factors.discrete import DiscreteFactor, TabularCPD
  from pgmpy.models import BayesianNetwork, MarkovNetwork
  from pgmpy.readwrite import UAIReader, UAIWriter
label_desc: Use image node_id 4 for calling the TestUAIWriterTorch obj's underlying member method code with example usage: obj.tearDown() without return types