code: def test_write_xmlbif_stateless(self):
      self.writer_stateless.write_xmlbif("grade_problem_output.xbif")
      with open("grade_problem_output.xbif", "r") as f:
          reader = XMLBIFReader(f)
      model = reader.get_model(state_name_type=int)
      self.assert_models_equivelent(self.model_stateless, model)
      self.assertDictEqual(
          {"D": [0, 1]}, model.get_cpds("D").state_names
      )
      os.remove("grade_problem_output.xbif")
  
imports: import os
  import unittest
  import xml.etree.ElementTree
  import numpy
  import numpy.testing
  from pgmpy import config
  from pgmpy.factors.discrete import TabularCPD
  from pgmpy.models import BayesianNetwork
  from pgmpy.readwrite import XMLBIFReader, XMLBIFWriter
label_desc: Use image node_id 3 for calling the TestXMLBIFWriterMethodsString obj's underlying member method code with example usage: obj.test_write_xmlbif_stateless() without return types