     
     /**
      The values of NSUnderlineStyleAttributeName and NSUnderlineColorAttributeName
+     
+     ### example
+     ```
+     "StringStylizer".stylize().underline(.StyleSingle, rgb: 0xff0000, alpha: 0.5).attr
+     ```
+     <img width="135" src="https://cloud.githubusercontent.com/assets/18320004/14389065/db66f77c-fdeb-11e5-8182-de300c85dc0e.png">
      
      - parameter style:NSUnderlineStyle...
      - parameter rgb:UInt? (default:nil)

    /**
     The values of NSStrokeWidthAttributeName and NSStrokeColorAttributeName
     
     - parameter color:UIColor
     - parameter alpha:Double (default:1.0)
     - parameter width:Double (default:1.0)

    /**
     The values of NSStrokeWidthAttributeName and NSStrokeColorAttributeName
     
     ### example
     ```
     "StringStylizer".stylize().stroke(rgb: 0xff0000, alpha: 1, width: 2).attr
     ```
     <img width="135" src="https://cloud.githubusercontent.com/assets/18320004/14389200/7fca9c74-fdec-11e5-996b-3ead1ac564cc.png">
     
     - parameter rgb:UInt? (default:nil)
     - parameter alpha:Double (default:1.0)
     - returns: StringStylizer<Styling>
