def has_change_permission(self, request, obj=None):
        return request.user.is_staff and (obj is not None) and (obj.id % 2 == 0)
Only allow changing objects with even id number
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.5/tests/regressiontests/admin_views/admin.py/RowLevelChangePermissionModelAdmin.has_change_permission