code: def get_cache_key(brain_or_object):
      
      key = [
          get_portal_type(brain_or_object),
          get_id(brain_or_object),
          get_uid(brain_or_object),
          # handle different domains gracefully
          get_url(brain_or_object),
          # Return the microsecond since the epoch in GMT
          get_modification_date(brain_or_object).micros(),
      ]
      return "-".join(map(lambda x: str(x), key))
docs: Generate a cache key for a common brain or object
  
      :param brain_or_object: A single catalog brain or content object
      :type brain_or_object: ATContentType/DexterityContentType/CatalogBrain
      :returns: Cache Key
      :rtype: str