--- a/test/data/schema.py	Fri Aug 08 13:05:07 2014 +0200
+++ b/test/data/schema.py	Mon Jul 28 16:05:19 2014 +0200
@@ -89,3 +89,8 @@
 
 class StateFull(WorkflowableEntityType):
     name = String()
+
+
+class Reference(EntityType):
+    nom = String(unique=True)
+    ean = String(unique=True, required=True)