             return stackArray.last
         }
     }
-}+}


class OHCircleSegue: UIStoryboardSegue {
    
    private static let expandDur: CFTimeInterval = 0.35
    private static let contractDur: CFTimeInterval = 0.15
    private static let stack = Stack()
    private static var isAnimating = false
    

    
    override init(identifier: String?, source: UIViewController, destination: UIViewController) {
        
        // By default, transition starts from the center of the screen,
        // so let's find the center when segue is first initialized
        let centerX = UIScreen.mainScreen().bounds.width*0.5
        let centerY = UIScreen.mainScreen().bounds.height*0.5
        let centerOfScreen = CGPointMake(centerX, centerY)
