docs: def to_dict(self, db_obj):
          """Create a Json-like dictionary for objects managed by this object
          store.
  
          Parameters
          ----------
          db_obj : (Sub-class of)ObjectHandle
  
          Returns
          -------
          (JSON)
              Json-like object, i.e., dictionary.
          """
          # Base Json serialization for database objects
          return {
              '_id' : db_obj.identifier,
              'timestamp' : str(db_obj.timestamp.isoformat()),
              'properties' : db_obj.properties}