Código:
atributoString.addAttribute(NSAttributedString.Key.strikethroughStyle, value: 1, range: NSMakeRange(0, atributoString.length)) precoSemDescontoLabel.attributedText = atributoString
Erro:
Value of type 'NSMutableString' has no member 'addAttribute'
Cannot assign value of type 'NSMutableString' to type 'NSAttributedString?'