From: Martin Probst <mail_at_martin-probst.com>
Date: Mon, 13 Jul 2009 16:09:08 +0200

> AFAIK It is the looking up of the implementation that is expensive:

Ah yes of course, I see. In that case it's pretty annoying that they
didn't make them thread safe. Maybe (hopefully) the change in the
JavaDoc is a progression in that direction ;-)

Martin