def parent(self):
pairs = self.__pairs<EOL>if len(pairs) <= <NUM_LIT:1>:<EOL><INDENT>return None<EOL><DEDENT>return Key(pairs=pairs[:-<NUM_LIT:1>], app=self.__app, namespace=self.__namespace)<EOL>
Return a Key constructed from all but the last (kind, id) pairs.

        If there is only one (kind, id) pair, return None.