Raizlabs/RZUtils — pull request #117 by ZevEisenberg (2014-12-17 19:44:15+00:00)
Title: Fix unbalanced called to begin/end appearance selectors

This is to fix a case I was seeing where we were calling `beginAppearanceTransition:animated` while `self.currentContentViewController` was still `nil`, and then calling `endAppearanceTransition` when it was no longer `nil`. This led to unbalanced calls.