 //
 
 import UIKit
+import Darwin
 
 /**
 This is a convenience subclass, which relieves you of the burden of keeping a 

        if (self.isInteractivelyPopping && operation == .Pop) {
            return self.interactivePopAnimator
        }
        return NonInteractiveAnimator(operation: operation)
    }
    
    func navigationController(navigationController: UINavigationController, interactionControllerForAnimationController animationController: UIViewControllerAnimatedTransitioning) -> UIViewControllerInteractiveTransitioning? {

    
}

private let defaultCancelPopDuration: NSTimeInterval = 0.16
private let maxBackViewTranslationPercentage: CGFloat = 0.30
private let minimumDismissalPercentage: CGFloat = 0.5
private let minimumThresholdVelocity: CGFloat = 100.0

private class InteractivePopAnimator: NSObject, UIViewControllerAnimatedTransitioning, UIViewControllerInteractiveTransitioning {
    
