MAINT: added code comment

src/caosdb/common/models.py

@@ -719,6 +719,14 @@ out: List[Entity]
         """
 
         for parent in self.parents:
+            # TODO:
+            # Comment on _wrap and _wrapped_entity
+            # Currently, I (henrik) do not why the wrapping is necessary (and it is not
+            # documented). However, the following illustrates, why I think, it is a bad idea.
+            # First you add a parent with rec.add_parent(parent), but then you cannot access
+            # attributes of parent when you use rec.parents[0] for example becasue you do not get
+            # the same object but a wrapping object and you need to know that you only get the
+            # original by accessing the private (!) _wrapped_entity object.
             w_parent = parent._wrapped_entity
             if retrieve:
                 parent.retrieve()