CSS HSL "linear-gradient" to Swift "CAGradientLayer"

Example.swift

// CSS gradient generated by https://www.joshwcomeau.com/gradient-generator/
// hsl(199deg 95% 55%) 0%
// hsl(140deg 63% 65%) 50%
// hsl(99deg 100% 50%) 100%

let gradient = CAGradientLayer()
// ...
gradient.type = .axial
gradient.colors = [
  UIColor.hsl(degrees: 199, saturation: 0.95, lightness: 0.55).cgColor,
  UIColor.hsl(degrees: 140, saturation: 0.63, lightness: 0.65).cgColor,
  UIColor.hsl(degrees:  99, saturation: 1.00, lightness: 0.50).cgColor
]
gradient.locations = [0, 0.5, 1]

UIColor+hsl.swift

import UIKit

extension UIColor {
  static func hsl(hue h: CGFloat, saturation s: CGFloat, lightness l: CGFloat, alpha a: CGFloat = 1.0) -> UIColor {
    var saturation: CGFloat = 0.0
    let brightness = l + s * min(l, 1 - l)
    if brightness == 0 {
      saturation = 0.0
    } else {
      saturation = 2 * (1 - l / brightness)
    }
    return UIColor(hue: h, saturation: saturation, brightness: brightness, alpha: a)
  }  
  static func hsl(degrees deg: CGFloat, saturation s: CGFloat, lightness l: CGFloat, alpha a: CGFloat = 1.0) -> UIColor {
    return UIColor.hsl(hue: deg / 360, saturation: s, lightness: l, alpha: a)
  }
}