 
     override func cancelTrackingWithEvent(event: UIEvent?) {
         super.cancelTrackingWithEvent(event)
-        print("cancel tracking")
     }
     
     

    var disabled:Bool = false {
        didSet {
            sliderBackgroundView.alpha = disabled ? 0.4 : 1.0
        }
    }
    

        sliderFillView.backgroundColor = tintColor
        
        handleLabel.frame = CGRectMake(0, 0, handleWidth, handleHeight)
        handleLabel.text = ""
        handleLabel.textAlignment = NSTextAlignment.Center
        handleLabel.textColor = UIColor.whiteColor()
        handleLabel.font = UIFont.systemFontOfSize(11, weight: UIFontWeightBold)
