diff -r c16c1805e973 -r 1ce12b716e71 cubicweb/server/session.py
--- a/cubicweb/server/session.py	Fri Mar 10 16:14:05 2017 +0100
+++ b/cubicweb/server/session.py	Fri Mar 10 16:31:08 2017 +0100
@@ -165,10 +165,6 @@
 DEFAULT_SECURITY = object()  # evaluated to true by design
 
 
-class SessionClosedError(RuntimeError):
-    pass
-
-
 def _open_only(func):
     """decorator for Connection method that check it is open"""
     @functools.wraps(func)