diff --git a/eventlet/hubs/libevent.py b/eventlet/hubs/libevent.py
index bab7f90..c6377c2 100644
--- a/eventlet/hubs/libevent.py
+++ b/eventlet/hubs/libevent.py
@@ -5,10 +5,10 @@
 # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 # copies of the Software, and to permit persons to whom the Software is
 # furnished to do so, subject to the following conditions:
-# 
+#
 # The above copyright notice and this permission notice shall be included in
 # all copies or substantial portions of the Software.
-# 
+#
 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -24,9 +24,6 @@ import time
 from eventlet.hubs import hub
 
 
-# XXX for debugging only
-#raise ImportError()
-
 try:
     # use rel if available
     import rel
@@ -39,7 +36,7 @@ except ImportError:
 import event
 
 
-class Hub(hub.BaseHub):    
+class Hub(hub.BaseHub):
     def __init__(self, clock=time.time):
         super(Hub, self).__init__(clock)
         self.interrupted = False
@@ -77,7 +74,7 @@ class Hub(hub.BaseHub):
 
     def signal_received(self, signal):
         # can't do more than set this flag here because the pyevent callback
-        # mechanism swallows exceptions raised here, so we have to raise in 
+        # mechanism swallows exceptions raised here, so we have to raise in
         # the 'main' greenlet (in wait()) to kill the program
         self.interrupted = True
         event.abort()
@@ -103,7 +100,7 @@ class Hub(hub.BaseHub):
         # raise any signals that deserve raising
         if self.interrupted:
             self.interrupted = False
-            raise KeyboardInterrupt() 
+            raise KeyboardInterrupt()
 
     def add_timer(self, timer):
         # store the pyevent timer object so that we can cancel later