zendframework/zf2 — pull request #5903 by ralphschindler (2014-03-03 21:47:13+00:00)
Title: Re-added ConstraintKeyObject which is consumed from the AbstractSource w/ test (Fixes #3512)

This re-adds the ConstraintKeyObject that was removed in a PR/addition last year.

#3512 is where this was identified, while no specific Db related issues address this.