refactor

Author: mkrd

dictdatabase/object_mapper.py

@@ -74,7 +74,10 @@ def _get_item_model(cls):
 			for type_args in get_args(base):
 				if issubclass(type_args, FileDictItemModel):
 					return type_args
-		raise AttributeError("FileDictModel must specify a FileDictItemModel")
+		raise AttributeError(
+			"FileDictModel must specify a FileDictItemModel "
+			"(e.g. Users(FileDictModel[User]))"
+		)
 
 
 	@classmethod