     var contentViewController: UIViewController!
     var fromView: UIView!
     private let popoverView = DKPopoverView()
+    
+    // MARK: - Observers
+    
+    private var preferredContentSizeObserver: NSKeyValueObservation?
     
     override open func loadView() {
         super.loadView()

            arrowPath.addLine(to: CGPoint(x: arrowWidth, y: arrowHeight))
            arrowPath.addLine(to: CGPoint(x: 0, y: arrowHeight))
            arrowPath.closeSubpath()

            context?.addPath(arrowPath)
            
            context?.setFillColor(UIColor.white.cgColor)
            context?.drawPath(using: CGPathDrawingMode.fill)

            let arrowImage = UIGraphicsGetImageFromCurrentImageContext()
            UIGraphicsEndImageContext()
            

    
    open class func dismissPopoverViewController() {
        let window = UIApplication.shared.keyWindow!
        
        for vc in window.rootViewController!.childViewControllers {
            if vc is DKPopoverViewController {
                (vc as! DKPopoverViewController).dismiss()
