[Zope] help with magic method "__of__"

OK so i'm a little slow. I know that Confera is not supported, but I am using it as a base for an extended version that would allow messages to be moved, reordered, copied, paseted, etc. In otherwords turn Messages into folderish? containerish? objects. I don't want to give up the indexing and searching though. Which leads me to believe that I need to override the 'setItem' and '__getitem__' maybe? Anyway As I've been reading the code over and over and over (two weeks now) and have thrown out three attempts. I keep seeing things like self.data[id].__of__(self) msg=msg.__of__(self) r=map(lambda x, p=self: x.__of__(p), r) How does the magic method '__of__()' work? Also how does intSet{} work? ta for any info. Karl Putland