symfony/symfony-docs — pull request #1083 by sberder-lm (2012-02-15 04:42:10+00:00)
Title: [HttpFoundation] [Request] add attributes property of Symfony\Component\HttpFoundation\Request object

The documentation was missing this property in Symfony\Component\HttpFoundation\Request.
I found it while debugging (print_r()-of-hell) and found out that it was not in the documentation.