class_docstr: Importer mock using PEP 451 APIs.
code: def create_module(self, spec):
      if spec.name not in self.modules:
          raise ImportError
      return self.modules[spec.name]
  
imports: import builtins
  import contextlib
  import errno
  import functools
  from importlib import machinery, util, invalidate_caches
  import marshal
  import os
  import os.path
  from test.support import import_helper
  from test.support import os_helper
  import unittest
  import sys
  import tempfile
  import types
label_desc: Use image node_id 2 for calling the mock_spec obj's underlying member method code with example usage: obj.create_module(spec) and returns: self