quiet reference doesn't throw exception

[Seth Rosenblum]

I'm using the velocity engine with ParseErrorException throwing turned
on because it greatly simplifies unit testing, as it just checks that
every value on the page has been filled in.  However, I'd like velocity
to not throw an exception when I pass it a quiet reference e.g. $isNull
should throw an exception, but $!isNull should just resolve to being
empty.  Is there a way to do this?
 
Thanks,
    Seth Rosenblum