Folder was missing.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@3203 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/Document/TradeCondition.py

@@ -53,6 +53,7 @@ class TradeCondition(Path):
                       , PropertySheet.XMLObject
                       , PropertySheet.CategoryCore
                       , PropertySheet.DublinCore
+                      , PropertySheet.Folder
                       , PropertySheet.Comment
                       , PropertySheet.Arrow
                       , PropertySheet.TradeCondition