class_docstr: Tests for the InspectLoader methods for FrozenImporter.
code: def test_get_source(self):
      # Should always return None.
      with import_helper.frozen_modules():
          result = self.machinery.FrozenImporter.get_source("__hello__")
      self.assertIsNone(result)
  
imports: from test.test_importlib import abc, util
  from test.support import captured_stdout, import_helper, STDLIB_DIR
  import contextlib
  import os.path
  import types
  import unittest
  import warnings
label_desc: Use image node_id 2 for calling the InspectLoaderTests obj's underlying member method code with example usage: obj.test_get_source() without return types