code: def test_get_variables(self):
      variables_expected = ["var_0", "var_1", "var_2"]
      self.assertListEqual(
          self.reader_string.variables, variables_expected
      )
      self.assertListEqual(
          self.reader_string_with_comment.variables, variables_expected
      )
  
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 3 for calling the TestUAIReaderTorch obj's underlying member method code with example usage: obj.test_get_variables() without return types