rubinius/rubinius — pull request #2402 by rmg (2013-06-28 20:43:31+00:00)
Title: Add ThreadGroup::Default, ThreadGroup#enclose, and ThreadGroup#enclosed?

Specs based on docs (http://www.ruby-doc.org/core-2.0/ThreadGroup.html) and running MRI 1.9.3.

I think this will fix #2389