documentcloud/backbone — pull request #1181 by braddunbar (2012-04-04 12:32:02+00:00)
Title: Fix #1179 - isValid returns true in the absence of validate.

As stated in #1179, `_validate` returns true in the absence of `validate`. This suggests that models without `validate` are valid models and that `isValid` should return true instead of throwing a TypeError.