144
144
workingtree.WorkingTreeFormat.register_format(format)
145
145
# which branch.Open will refuse (not supported)
146
146
self.assertRaises(errors.UnsupportedFormatError, workingtree.WorkingTree.open, '.')
149
147
# but open_downlevel will work
150
148
self.assertEqual(format.open(dir), workingtree.WorkingTree.open_downlevel('.'))