asyncio: Add __weakref__ slots to Handle and CoroWrapper. Upstream issue #166.
diff --git a/Lib/asyncio/events.py b/Lib/asyncio/events.py
index 57af68a..31592d1 100644
--- a/Lib/asyncio/events.py
+++ b/Lib/asyncio/events.py
@@ -16,7 +16,7 @@
 class Handle:
     """Object returned by callback registration methods."""
 
-    __slots__ = ['_callback', '_args', '_cancelled', '_loop']
+    __slots__ = ['_callback', '_args', '_cancelled', '_loop', '__weakref__']
 
     def __init__(self, callback, args, loop):
         assert not isinstance(callback, Handle), 'A Handle is not a callback'