class private func makeImage(_ color: UIColor) -> UIImage? {
let rect = CGRect(x: 0.0, y: 0.0, width: 1.0, height: 1.0)
UIGraphicsBeginImageContext(rect.size)
let context = UIGraphicsGetCurrentContext()
context?.setFillColor(color.cgColor)
context?.fill(rect)
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return image
}