Finder Idea for servlets facing multithreading issues

Hello,

I'm missing a finder that detects the problem described here: 
http://www.javaworld.com/javaworld/jw-07-2004/jw-0712-threadsafe.html.

It should not be to hard to write, for someone familiar with writing 
FindBugs bug detectors :-).


Regards,

Andreas.