+ if memoize:
+ memo_args = (getattr(self, "%s_id" % self._mptt_meta.parent_attr), getattr(root, 'pk', None), pathsep, getattr(self, field, '?'))
+ try:
+ return self._path_memo[memo_args]
+ except AttributeError:
+ self._path_memo = {}
+ except KeyError:
+ pass
+