ChartFill doesn't seem to work - or I'm just not understanding it

I'm using a filled line chart. I want to have a simple gradient from one color to another. All I'm seeing is a single color, no matter if I use a gradient or not.

Here is my code chunks :)

` fileprivate let set_checkin = LineChartDataSet(values: [ChartDataEntry()], label: "Checkins")
`

Yes - its ugly orange to green - its for testing just to see if it works:

` let checkinColors = [UIColor.orange, UIColor.green]
set_checkin.fillAlpha = 1.0
set_checkin.fill = Fill(linearGradient: CGGradient.gradient(withUIColors: checkinColors), angle: 90.0)
set_checkin.drawFilledEnabled = true
`
And here is my gradient extension - I've tried multiple ways to create Gradients - but I just left this one.

`
extension CGGradient {
class func gradient(withUIColors colors: [UIColor]) -> CGGradient {
var colorFloats = [CGFloat]()

for color in colors {
var rSelf:CGFloat = 0, gSelf:CGFloat = 0, bSelf:CGFloat = 0, alpha:CGFloat = 0
color.getRed(&rSelf, green: &gSelf, blue: &bSelf, alpha: &alpha)
colorFloats.append(rSelf)
colorFloats.append(gSelf)
colorFloats.append(bSelf)
colorFloats.append(alpha)
}

let colorSpace = CGColorSpaceCreateDeviceRGB()
return CGGradient(colorSpace: colorSpace, colorComponents: colorFloats, locations: nil, count: colors.count)!
}
}
`
But all I get is a solid color - the first one in the gradient.

Start by reproducing the provided Swift setup using LineChartDataSet, Fill, and the CGGradient extension. Trace how the filled line chart consumes the gradient and compare it with the reported solid first color; done means the filled chart visibly renders the orange-to-green gradient.

Written by the indexing model from the issue text.