#NEWLINE# def get_rendering_cache_key( placeholder_name , contentitem ) : #NEWLINE# #INDENT# '\n    Return a cache key for the content item output.\n\n    .. seealso::\n\n        The :func:`ContentItem.clear_cache() <fluent_contents.models.ContentItem.clear_cache>` function\n        can be used to remove the cache keys of a retrieved object.\n    ' #NEWLINE# if ( not contentitem . pk ) : #NEWLINE# #INDENT# return None #NEWLINE# #UNINDENT# return 'contentitem.@{0}.{1}.{2}' . format ( placeholder_name , contentitem . plugin . type_name , contentitem . pk )