code: def test_frozen(self):
      name = "__hello__"
      if name in sys.modules:
          del sys.modules[name]
      with import_helper.frozen_modules():
          import __hello__
      with captured_stdout() as out:
          __hello__.main()
      self.assertEqual(out.getvalue(), "Hello world!\n")
  
file_path: cpython/Lib/test/test_frozen.py
imports: import importlib.machinery
  import sys
  import unittest
  from test.support import captured_stdout, import_helper
label_desc: Use image node_id 1 for calling the TestFrozen obj's underlying member method code with example usage: obj.test_frozen() without return types