I am wondering what sort of OO / Java / C++ knowledge you acutally have. You are not understanding what I say, and I am not in the mood to explain at greater length now.
Dear Tim,
Perhaps I am not explaining myself, so I have drawn a class digram - attached.
Kind regards,
Gareth
The only way to keep this discussion from going belly up is to do what Marina says and test the course format renderers, and if they are found to be flawed then file it as a BUG in Moodle Tracker.
I'm too tired to read, and not knowledgeable enough about renderers to comment, although I have discovered a wonderful way to include plugin renderers in themes thanks to Tim, so I guess he knows what he is talking about.
Have a nice weekend everyone. Please don't spend it 
Don't worry be happy! 
Well, they say a picture is worth 1000 words, and your picture certainly qualifies. It is exactly right. Sorry I failed to understand what you were saying before.
Dear Tim,
No worries - just goes to show why class, object interaction, state transition diagrams... exist to describe the form and function of software.
Cheers,
Gareth