new_contents: # Copyright 2011 OpenStack Foundation.
  # All Rights Reserved.
  #
  #    Licensed under the Apache License, Version 2.0 (the "License"); you may
  #    not use this file except in compliance with the License. You may obtain
  #    a copy of the License at
  #
  #         http://www.apache.org/licenses/LICENSE-2.0
  #
  #    Unless required by applicable law or agreed to in writing, software
  #    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  #    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  #    License for the specific language governing permissions and limitations
  #    under the License.
  
  """Local storage of variables using weak references"""
  
  import threading
  import weakref
  
  
  class WeakLocal(threading.local):
      def __getattribute__(self, attr):
          rval = super(WeakLocal, self).__getattribute__(attr)
          if rval:
              # NOTE(mikal): this bit is confusing. What is stored is a weak
              # reference, not the value itself. We therefore need to lookup
              # the weak reference and return the inner value here.
              rval = rval()
          return rval
  
      def __setattr__(self, attr, value):
          value = weakref.ref(value)
          return super(WeakLocal, self).__setattr__(attr, value)
  
  
  # NOTE(mikal): the name "store" should be deprecated in the future
  store = WeakLocal()
  
  # A "weak" store uses weak references and allows an object to fall out of scope
  # when it falls out of scope in the code that uses the thread local storage. A
  # "strong" store will hold a reference to the object so that it never falls out
  # of scope.
  weak_store = WeakLocal()
  strong_store = threading.local()
  
subject: Add local module which was omitted before.