How to set NSAttributedString range?

In XCode 10 and swift 4 I used this way:

let customizedText = NSMutableAttributedString(string: "My Text")
customizedText.addAttribute(NSAttributedString.Key.strokeWidth, value: 5.0, range: NSRange(location: 0, length: customizedText.string.count))
customizedText.addAttribute(NSAttributedString.Key.strokeColor, value: #colorLiteral(red: 0.5725490451, green: 0, blue: 0.2313725501, alpha: 1), range: NSRange(location: 0, length: customizedText.string.count))
myLabel.attributedText = customizedText

Don't use magic numbers

let baseString = "Don't use magic numbers."

let attributedString = NSMutableAttributedString(string: baseString, attributes: nil)

let dontRange = (attributedString.string as NSString).range(of: "Don't")
attributedString.setAttributes([NSFontAttributeName: UIFont.boldSystemFont(ofSize: 18)], range: dontRange)

So meta