General code cleanup.

 - Add explicit dependency on zope.event in setup.py.
 - Use Python 3 compatible syntax for specifying that a class implements an
   interface, i.e. the @implementer class decorator.
 - print_function futures.
 - Whitespace normalization.

1 files changed, 3 insertions, 5 deletions

diff --git a/src/mailman/chains/moderation.py b/src/mailman/chains/moderation.py
index 9f9633346..6c2ed1180 100644
--- a/src/mailman/chains/moderation.py
+++ b/src/mailman/chains/moderation.py
@@ -34,7 +34,7 @@ made as to the disposition of the message.  `defer` is the default for
 members, while `hold` is the default for nonmembers.
 """
 
-from __future__ import absolute_import, unicode_literals
+from __future__ import absolute_import, print_function, unicode_literals
 
 __metaclass__ = type
 __all__ = [
@@ -42,7 +42,7 @@ __all__ = [
     ]
 
 
-from zope.interface import implements
+from zope.interface import implementer
 
 from mailman.chains.base import Link
 from mailman.config import config
@@ -52,15 +52,13 @@ from mailman.interfaces.chain import IChain, LinkAction
 
 
 
+@implementer(IChain)
 class ModerationChain:
     """Dynamically produce a link jumping to the appropriate terminal chain.
 
     The terminal chain will be one of the Accept, Hold, Discard, or Reject
     chains, based on the member's or nonmember's moderation action setting.
     """
-
-    implements(IChain)
-
     name = 'moderation'
     description = _('Moderation chain')