code: def test_nested(self):
      pkgutil_boilerplate = (
          "import pkgutil; "
          "__path__ = pkgutil.extend_path(__path__, __name__)"
      )
      self.create_module("a.pkg.__init__", pkgutil_boilerplate)
      self.create_module("b.pkg.__init__", pkgutil_boilerplate)
      self.create_module("a.pkg.subpkg.__init__", pkgutil_boilerplate)
      self.create_module("b.pkg.subpkg.__init__", pkgutil_boilerplate)
      self.create_module("a.pkg.subpkg.c", "c = 1")
      self.create_module("b.pkg.subpkg.d", "d = 2")
      sys.path.insert(0, os.path.join(self.basedir, "a"))
      sys.path.insert(0, os.path.join(self.basedir, "b"))
      import pkg
  
      self.addCleanup(unload, "pkg")
      self.assertEqual(len(pkg.__path__), 2)
      import pkg.subpkg
  
      self.addCleanup(unload, "pkg.subpkg")
      self.assertEqual(len(pkg.subpkg.__path__), 2)
      from pkg.subpkg.c import c
      from pkg.subpkg.d import d
  
      self.assertEqual(c, 1)
      self.assertEqual(d, 2)
  
imports: from pathlib import Path
  from test.support.import_helper import unload, CleanImport
  from test.support.warnings_helper import check_warnings, ignore_warnings
  import unittest
  import sys
  import importlib
  from importlib.util import spec_from_file_location
  import pkgutil
  import os
  import os.path
  import tempfile
  import shutil
  import zipfile
label_desc: Use image node_id 4 for calling the NestedNamespacePackageTest obj's underlying member method code with example usage: obj.test_nested() without return types