diff -r 058bb3dc685f -r 0b59724cb3f2 cubicweb/web/test/data/entities.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cubicweb/web/test/data/entities.py	Sat Jan 16 13:48:51 2016 +0100
@@ -0,0 +1,31 @@
+# copyright 2015 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
+# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr
+#
+# This file is part of CubicWeb.
+#
+# CubicWeb is free software: you can redistribute it and/or modify it under the
+# terms of the GNU Lesser General Public License as published by the Free
+# Software Foundation, either version 2.1 of the License, or (at your option)
+# any later version.
+#
+# CubicWeb is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Lesser General Public License along
+# with CubicWeb.  If not, see <http://www.gnu.org/licenses/>.
+
+from cubicweb.predicates import is_instance
+from cubicweb.entities.adapters import ITreeAdapter
+from cubicweb.entities import AnyEntity, fetch_config
+
+
+class TreeNode(AnyEntity):
+    __regid__ = 'TreeNode'
+    fetch_attrs, cw_fetch_order = fetch_config(['name'])
+
+
+class ITreeNode(ITreeAdapter):
+    __select__ = is_instance('TreeNode')
+    tree_relation = 'parent'