code: def test_module_has_no_spec(self):
      module_name = "doesnotexist"
      assert module_name not in pyclbr._modules
      with test_importlib_util.uncache(module_name):
          with self.assertRaises(ModuleNotFoundError):
              pyclbr.readmodule_ex(module_name)
  
imports: import sys
  from textwrap import dedent
  from types import FunctionType, MethodType, BuiltinFunctionType
  import pyclbr
  from unittest import TestCase, main
  from test.test_importlib import util
  import warnings
label_desc: Use image node_id 4 for calling the ReadmoduleTests obj's underlying member method code with example usage: obj.test_module_has_no_spec() without return types