code: def test_mixed_types_filenames(self):
      # cannot pass filenames as bytes if content is str (this may not be
      # the right behaviour, but at least the test demonstrates how
      # things work)
      a = ["hello\n"]
      b = ["ohell\n"]
      fna = b"ol\xe9.txt"  # filename transcoded from ISO-8859-1
      fnb = b"ol\xc3a9.txt"  # to UTF-8
      self._assert_type_error(
          "all arguments must be str, not: b'ol\\xe9.txt'",
          difflib.unified_diff,
          a,
          b,
          fna,
          fnb,
      )
  
imports: import difflib
  from test.support import findfile
  import unittest
  import doctest
  import sys
label_desc: Use image node_id 5 for calling the TestBytes obj's underlying member method code with example usage: obj.test_mixed_types_filenames() without return types