URLyBird Interfaces

Hi All,
I have recently downloaded the Question for SCJD in which i got URLyBird. I see a lot of people talking of LockManager, DBMain, DBMainImpl. I do not see the mention of these classes in the Document. The Document is just 8 pages. Am i missing out something?
Kinds Regards,

I haven't seen URLYBird. But I don't think you are missing anything. The document doesn't go into a lot of details about How you write your code.

For example it would just say 'This is how locking should work' But it is upto you to decide on things like 'should I have a class dedicated to managing locks? Should I call it lock manager? etc. Keep searching this forum about locking and you would get a lot of useful tips

Thanks for the help. I thought may be i skipped some pages. But now i know it is just that people have been giving these names on their own.