 // DO SEE http://stackoverflow.com/questions/1191868/uiimageview-scaling-interpolation
 // see http://stackoverflow.com/questions/3514066/how-to-tint-a-transparent-png-image-in-iphone
 
-// TODO: find and remove all !
-
 /// A view for rendering audio waveforms
 // @IBDesignable
 open class FDWaveformView: UIView {

            context.addLine(to: CGPoint(x: CGFloat(x), y: verticalMiddle + height))
            context.strokePath();
        }
        let image = UIGraphicsGetImageFromCurrentImageContext()
        let drawRect = CGRect(x: 0, y: 0, width: (image?.size.width)!, height: (image?.size.height)!)
        context.setFillColor(progressColor.cgColor)
        UIRectFillUsingBlendMode(drawRect, .sourceAtop)
        let tintedImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        done(image!, tintedImage!)
    }
}


        var scaledWidth: CGFloat = 1.0
        if cachedSampleRange.count > 0 && zoomSamples.count > 0 {
            scaledX = CGFloat(cachedSampleRange.lowerBound - zoomSamples.lowerBound) / CGFloat(zoomSamples.count)
            scaledWidth = CGFloat(cachedSampleRange.last! - zoomSamples.lowerBound) / CGFloat(zoomSamples.count)    // forced unwrap is safe
            scaledProgressWidth = CGFloat(progressSamples - zoomSamples.lowerBound) / CGFloat(zoomSamples.count)
        }
        let childFrame = CGRect(x: frame.width * scaledX, y: 0, width: frame.width * scaledWidth, height: frame.height)
