About your answer
I just have one question about your reply though, if you don't mind.
What is meant by this:
" GuessGame is a JFrame, but doesn't make any use of being as such. Instead it invokes its own JFrame and shows that, so this means you cannot call any component specific calls on the nested classes without providing an object to work with since the JFrame that would resolve to the implicit "this" of the parent wouldn't have any impact on the existing gui."
This part left me a little lost.