code: def test_get_variables(self):
      self.assertListEqual(
          sorted(list(self.reader_string.get_variables())),
          ["a", "b", "c", "d", "e", "f"],
      )
      self.assertListEqual(
          sorted(list(self.reader_file.get_variables())),
          ["a", "b", "c", "d", "e", "f"],
      )
      self.assertEqual(
          self.reader_string.get_variables()["a"]["TYPE"], "discrete"
      )
      self.assertEqual(
          self.reader_string.get_variables()["a"]["XPOS"], "13495"
      )
      self.assertEqual(
          self.reader_string.get_variables()["a"]["YPOS"], "10465"
      )
      self.assertEqual(
          self.reader_string.get_variables()["a"]["DESCRIPTION"],
          "(a) Metastatic Cancer",
      )
      self.assertListEqual(
          self.reader_string.get_variables()["a"]["STATES"],
          ["Present", "Absent"],
      )
      self.assertEqual(
          self.reader_file.get_variables()["a"]["TYPE"], "discrete"
      )
      self.assertEqual(
          self.reader_file.get_variables()["a"]["XPOS"], "13495"
      )
      self.assertEqual(
          self.reader_file.get_variables()["a"]["YPOS"], "10465"
      )
      self.assertEqual(
          self.reader_file.get_variables()["a"]["DESCRIPTION"],
          "(a) Metastatic Cancer",
      )
      self.assertListEqual(
          self.reader_file.get_variables()["a"]["STATES"],
          ["Present", "Absent"],
      )
  
imports: import io
  import sys
  import unittest
  import xml.etree.ElementTree
  import networkx
  import numpy
  import numpy.testing
  from pgmpy.factors.discrete import TabularCPD
  from pgmpy.models import BayesianNetwork
  from pgmpy.readwrite import XMLBeliefNetwork
label_desc: Use image node_id 6 for calling the TestXBNReaderTorch obj's underlying member method code with example usage: obj.test_get_variables() without return types