[kupfer] Pickle obj.base's _NonpersistentToken to None using sum

[Ulrik Sverdrup <usverdrup src gnome org>]

commit ebd8c908004baa8a779e9db5786c826891611a76
Author: Ulrik Sverdrup <ulrik sverdrup gmail com>
Date:   Sun Jan 24 22:28:32 2010 +0100

    Pickle obj.base's _NonpersistentToken to None using sum
    
    Simply reducing the token to the call 'sum((), None)' that always
    returns None is enough.

 kupfer/obj/base.py |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/kupfer/obj/base.py b/kupfer/obj/base.py
index 5f659b6..4b10fae 100644
--- a/kupfer/obj/base.py
+++ b/kupfer/obj/base.py
@@ -158,7 +158,7 @@ class _NonpersistentToken (object):
 	def __nonzero__(self):
 		return bool(self.object)
 	def __reduce__(self):
-		return (eval, ("None", ))
+		return (sum, ((), None))
 
 class Leaf (KupferObject):
 	"""