Comment

synapse/handlers/federation.py

@@ -252,6 +252,8 @@ class FederationHandler(BaseHandler):
             except:
                 return False
 
+        # Parses mapping `event_id -> (type, state_key) -> state event_id`
+        # to get all state ids that we're interested in.
         event_map = yield self.store.get_events([
             e_id
             for key_to_eid in event_to_state_ids.values()