Allow to define reverse Multilinks Now it's possible to specify a rev_multilink parameter when creating Link or Multilink properties. The parameter takes a property name to be inserted into the linked-to class. It allows to navigate from the other side of the link as if it where a forward Multilink using the existing data structures.

--- a/test/memorydb.py	Sun Apr 12 21:03:55 2020 +0100
+++ b/test/memorydb.py	Wed Apr 29 16:30:27 2020 +0200
@@ -243,7 +243,7 @@
         return len(self.getfile(classname, nodeid, property))
 
     def post_init(self):
-        pass
+        super(Database, self).post_init()
 
     def refresh_database(self):
         pass