override func touchesEnded(_ touches: Set<UITouch>,with event: UIEvent?) {
    if let firstTouch = touches.first {
        let hitView = self.view.hitTest(firstTouch.location(in: self.view),with: event)

        if hitView === viewB {
            print("touch is inside")
        } else {
            print("touch is outside")
        }
    }
}