Superviews not visible

[zernoff21]

Hello!

You should insert the gradient layer as the first layer, so superviews are not overlaid by the gradient.

private func installGradient() {
        // if there's already a gradient installed on the layer, remove it
        if let gradient = self.gradient {
            gradient.removeFromSuperlayer()
        }
        let gradient = createGradient()
        //self.layer.addSublayer(gradient)
        self.layer.insertSublayer(gradient, at: 0)
        self.gradient = gradient
    }