Trivial bug fix:  deque == []  is not a good way to check if a deque is empty.
diff --git a/Lib/asynchat.py b/Lib/asynchat.py
index 062ab3e..28b89a2 100644
--- a/Lib/asynchat.py
+++ b/Lib/asynchat.py
@@ -259,7 +259,7 @@
         return len(self.list)
 
     def is_empty (self):
-        return self.list == []
+        return not self.list
 
     def first (self):
         return self.list[0]