code: def test_callback_None_index(self):
      def myreplace(exc):
          return ("x", None)
  
      codecs.register_error("test.cjktest", myreplace)
      self.assertRaises(
          TypeError, self.encode, self.unmappedunicode, "test.cjktest"
      )
  
imports: import codecs
  import os
  import re
  import sys
  import unittest
  from http.client import HTTPException
  from test import support
  from io import BytesIO
label_desc: Use image node_id 9 for calling the TestBase obj's underlying member method code with example usage: obj.test_callback_None_index() and returns: str,  None