[#8538] add new get_object_from_id timeline helper method which tries to find an object from an allura_id
diff --git a/Allura/allura/model/timeline.py b/Allura/allura/model/timeline.py
index 9048b6c..6c343bd 100644
--- a/Allura/allura/model/timeline.py
+++ b/Allura/allura/model/timeline.py
@@ -138,7 +138,11 @@
     allura_id = get_allura_id(activity_object_dict)
     if not allura_id:
         return None
-    classname, _id = allura_id.split(':', 1)
+    return get_object_from_id(allura_id)
+
+
+def get_object_from_id(node_id):
+    classname, _id = node_id.split(':', 1)
     cls = Mapper.by_classname(classname).mapped_class
     try:
         _id = bson.ObjectId(_id)