--- a/sat/plugins/plugin_xep_0060.py	Wed Jul 20 17:12:29 2022 +0200
+++ b/sat/plugins/plugin_xep_0060.py	Wed Jul 20 17:18:17 2022 +0200
@@ -725,7 +725,9 @@
         @param node (str): node id.
         @param max_items (int): optional limit on the number of retrieved items.
         @param item_ids (list[str]): identifiers of the items to be retrieved (can't be
-                                     used with rsm_request).
+             used with rsm_request). If requested items don't exist, they won't be
+             returned, meaning that we can have an empty list as result (NotFound
+             exception is NOT raised).
         @param sub_id (str): optional subscription identifier.
         @param rsm_request (rsm.RSMRequest): RSM request data
         @return: a deferred couple (list[dict], dict) containing:

--- a/sat/tools/utils.py	Wed Jul 20 17:12:29 2022 +0200
+++ b/sat/tools/utils.py	Wed Jul 20 17:18:17 2022 +0200
@@ -18,6 +18,7 @@
 
 """ various useful methods """
 
+from typing import Optional, Union
 import unicodedata
 import os.path
 import datetime
@@ -137,7 +138,10 @@
     return wrapper
 
 
-def xmpp_date(timestamp=None, with_time=True):
+def xmpp_date(
+    timestamp: Optional[Union[float, int]] = None,
+    with_time: bool = True
+) -> str:
     """Return date according to XEP-0082 specification
 
     to avoid reveling the timezone, we always return UTC dates