code: def _check_io_encoding(self, module, encoding=None, errors=None):
      filename = __file__
  
      # Encoding explicitly set
      args = []
      if encoding:
          args.append(f"encoding={encoding!r}")
      if errors:
          args.append(f"errors={errors!r}")
      code = (
          textwrap.dedent(
              """
              import sys
              from %s import open
              filename = sys.argv[1]
              with open(filename, %s) as fp:
                  print(f"{fp.encoding}/{fp.errors}")
          """
          )
          % (module, ", ".join(args))
      )
      out = self.get_output("-c", code, filename, PYTHONUTF8="1")
  
      if not encoding:
          encoding = "utf-8"
      if not errors:
          errors = "strict"
      self.assertEqual(out.lower(), f"{encoding}/{errors}")
  
imports: import locale
  import subprocess
  import sys
  import textwrap
  import unittest
  from test import support
  from test.support.script_helper import assert_python_ok, assert_python_failure
  from test.support import os_helper, MS_WINDOWS
label_desc: Use image node_id 9 for calling the UTF8ModeTests obj's underlying member method code with example usage: obj._check_io_encoding(module, encoding, errors) without return types