code: def test_bjunk(self):
      sm = difflib.SequenceMatcher(
          isjunk=lambda x: x == " ",
          a="a" * 40 + "b" * 40,
          b="a" * 44 + "b" * 40,
      )
      self.assertEqual(sm.bjunk, set())
  
      sm = difflib.SequenceMatcher(
          isjunk=lambda x: x == " ",
          a="a" * 40 + "b" * 40,
          b="a" * 44 + "b" * 40 + " " * 20,
      )
      self.assertEqual(sm.bjunk, {" "})
  
      sm = difflib.SequenceMatcher(
          isjunk=lambda x: x in [" ", "b"],
          a="a" * 40 + "b" * 40,
          b="a" * 44 + "b" * 40 + " " * 20,
      )
      self.assertEqual(sm.bjunk, {" ", "b"})
  
imports: import difflib
  from test.support import findfile
  import unittest
  import doctest
  import sys
label_desc: Use image node_id 3 for calling the TestWithAscii obj's underlying member method code with example usage: obj.test_bjunk() without return types