--- a/roundup/roundupdb.py	Thu Feb 27 10:05:38 2025 +0100
+++ b/roundup/roundupdb.py	Sat Mar 01 13:08:09 2025 +0100
@@ -197,7 +197,7 @@
     pass
 
 
-# deviation from spec - was called IssueClass
+# deviation from spec - was called ItemClass
 class IssueClass:
     """This class is intended to be mixed-in with a hyperdb backend
     implementation. The backend should provide a mechanism that
@@ -228,6 +228,27 @@
         ''"actor", ''"activity", ''"creator", ''"creation",
     )
 
+    def _update_properties(self, classname, properties):
+        """The newly-created class automatically includes the "messages",
+        "files", "nosy", and "superseder" properties.  If the 'properties'
+        dictionary attempts to specify any of these properties or a
+        "creation", "creator", "activity" or "actor" property, a ValueError
+        is raised. This method must be called by __init__.
+
+        """
+        if 'title' not in properties:
+            properties['title'] = hyperdb.String(indexme='yes')
+        if 'messages' not in properties:
+            properties['messages'] = hyperdb.Multilink("msg")
+        if 'files' not in properties:
+            properties['files'] = hyperdb.Multilink("file")
+        if 'nosy' not in properties:
+            # note: journalling is turned off as it really just wastes
+            # space. this behaviour may be overridden in an instance
+            properties['nosy'] = hyperdb.Multilink("user", do_journal="no")
+        if 'superseder' not in properties:
+            properties['superseder'] = hyperdb.Multilink(classname)
+
     # New methods:
     def addmessage(self, issueid, summary, text):
         """Add a message to an issue's mail spool.