func alignment(alignment: NSTextAlignment, subString: String) {
        if let range = self.string.range(of: subString) {
            self.alignment(alignment: alignment, onRange: NSRange(range, in: self.string))
        }
    }
    func alignment(alignment: NSTextAlignment, onRange: NSRange) {
        let paragraphStyle = NSMutableParagraphStyle()
        paragraphStyle.alignment = alignment
        self.addAttributes([NSAttributedString.Key.paragraphStyle : paragraphStyle], range: onRange)
    }