[SWIFT]NSMutableAttributedString Extention

extension NSMutableAttributedString {
    
    /// 문자열 특정범위 폰트/컬러 속성변경
    func setAttribute(font: UIFont, color: UIColor, start: Int, length: Int) {
        self.addAttributes([NSAttributedString.Key.font: font, NSAttributedString.Key.foregroundColor: color],
                           range: NSMakeRange(start, length))
    }
}