diff --git a/test/tc_aggs.rb b/test/tc_aggs.rb
index <HASH>..<HASH> 100644
--- a/test/tc_aggs.rb
+++ b/test/tc_aggs.rb
@@ -91,6 +91,7 @@ class PriorityQ
   end
 end
 
+# XXX: not used by any tests
 class DupAggs
   include Bud
Mark unused code in test case.