code: def test_exec_valid_coding(self):
      d = {}
      exec(b'# coding: cp949\na = "\xaa\xa7"\n', d)
      self.assertEqual(d["a"], "\u3047")
  
imports: import unittest
  from test.support import script_helper, captured_stdout, requires_subprocess, requires_resource
  from test.support.os_helper import TESTFN, unlink, rmtree
  from test.support.import_helper import unload
  import importlib
  import os
  import sys
  import subprocess
  import tempfile
label_desc: Use image node_id 12 for calling the MiscSourceEncodingTest obj's underlying member method code with example usage: obj.test_exec_valid_coding() without return types