old_contents: COUNTER_KEY = 'testapp:counter'
  REDIS_HOST = 'localhost'
  REDIS_PORT = 6379
  REDIS_DB = 0
  
new_contents: COUNTER_KEY = 'testapp:counter'
  REDIS_HOST = 'localhost'
  REDIS_PORT = 6379
  REDIS_DB = 0
  
  
  try:
      import settings_local
  except ImportError:
      pass
  else:
      for attr in dir(settings_local):
          if attr.startswith('_'):
              continue
          locals()[attr] = getattr(settings_local, attr)
  
subject: Load local settings for testapp if any.