code: def test_subinterp(self):
      # bpo-42846: Test a CJK codec in a subinterpreter
      import _testcapi
  
      encoding = "cp932"
      text = "Python の開発は、1990 年ごろから開始されています。"
      code = (
          textwrap.dedent(
              """
              import codecs
              encoding = %r
              text = %r
              encoder = codecs.getincrementalencoder(encoding)()
              text2 = encoder.encode(text).decode(encoding)
              if text2 != text:
                  raise ValueError(f"encoding issue: {text2!a} != {text!a}")
          """
          )
          % (encoding, text)
      )
      res = _testcapi.run_in_subinterp(code)
      self.assertEqual(res, 0)
  
imports: import _multibytecodec
  import codecs
  import io
  import sys
  import textwrap
  import unittest
  from test import support
  from test.support import os_helper
  from test.support.os_helper import TESTFN
label_desc: Use image node_id 10 for calling the Test_IncrementalEncoder obj's underlying member method code with example usage: obj.test_subinterp() without return types