const char *
_notmuch_message_get_thread_id_only(notmuch_message_t *message);
+size_t _notmuch_message_get_thread_depth (notmuch_message_t *message);
+
+void
+_notmuch_message_label_depths (notmuch_message_t *message,
+ size_t depth);
+
notmuch_message_list_t *
_notmuch_message_sort_subtrees (void *ctx, notmuch_message_list_t *list);