I have a UIViewController vc1 which is pushed after UIViewController vc2. 
Both vc1 and vc2 are with transparent background.
Problem:
When I try to pop vc2 with interactive pop gesture (pan from edge), in my view stack appears mysterious UIParallaxDimmingView which darkens my stack (under transparent view controllers there is a background image). 
As soon as I release finger, cancel or finish transition it becomes clear/transparent again.
How can i disable/remove UIParallaxDimmingView or set it transparent?