             if oldValue != bounds {
 
                 // If busy_loadingView is in the view hierarchy
-                if let superView = busy_loadingView?.superview {
+                if let _ = busy_loadingView?.superview {
 
                     // Remove loadingView
                     busy_loadingView?.removeFromSuperview()

    }

    func maskLayer() -> CALayer {
        var alphaLayer = CAGradientLayer()
        alphaLayer.frame = bounds
        alphaLayer.colors = [UIColor(red: 0, green: 0, blue: 0, alpha: 0).CGColor, UIColor(red: 0, green: 0, blue: 0, alpha: 0.2).CGColor]
        return alphaLayer

            return objc_getAssociatedObject(self, &BusyNavigationBarLoadingViewAssociationKey) as? UIView
        }
        set(newValue) {
            objc_setAssociatedObject(self, &BusyNavigationBarLoadingViewAssociationKey, newValue, .OBJC_ASSOCIATION_RETAIN)
        }
    }

