code: def test_load_submodule(self):
      # Test loading a simulated submodule.
      module = self.load_module_by_name("pkg." + self.name)
      self.assertIsInstance(module, types.ModuleType)
      self.assertEqual(module.__name__, "pkg." + self.name)
      self.assertEqual(module.str_const, "something different")
  
imports: from test.test_importlib import abc, util
  import os.path
  import sys
  import types
  import unittest
  import warnings
  import importlib.util
  import importlib
  from test.support import MISSING_C_DOCSTRINGS
label_desc: Use image node_id 8 for calling the MultiPhaseExtensionModuleTests obj's underlying member method code with example usage: obj.test_load_submodule() without return types