--- a/sat/plugins/plugin_xep_0059.py	Sun Dec 09 14:07:26 2018 +0100
+++ b/sat/plugins/plugin_xep_0059.py	Mon Dec 10 20:34:45 2018 +0100
@@ -74,6 +74,33 @@
         else:
             return None
 
+    def serialise(self, rsm_response, data=None):
+        """Serialise data for RSM
+
+        Key set in data can be:
+            - rsm_first: first item id in the page
+            - rsm_last: last item id in the page
+            - rsm_index: position of the first item in the full set (may be approximate)
+            - rsm_count: total number of items in the full set (may be approximage)
+        If a value doesn't exists, it's not set.
+        All values are set as strings.
+        @param rsm_response(rsm.RSMResponse): response to serialise
+        @param data(dict, None): dict to update with rsm_* data.
+            If None, a new dict is created
+        @return (dict): data dict
+        """
+        if data is None:
+            data = {}
+        if rsm_response.first is not None:
+            data[u"rsm_first"] = rsm_response.first
+        if rsm_response.last is not None:
+            data[u"rsm_last"] = rsm_response.last
+        if rsm_response.index is not None:
+            data[u"rsm_index"] = unicode(rsm_response.index)
+        if rsm_response.index is not None:
+            data[u"rsm_index"] = unicode(rsm_response.index)
+        return data
+
 
 class XEP_0059_handler(xmlstream.XMPPHandler):
     implements(iwokkel.IDisco)