      
      ### example
      ```
+     
+     
      "StringStylizer".stylize().font(UIFont(name: "Copperplate-Light", size: 17)!).attr
+     
      ```
      <img width="163" src="https://cloud.githubusercontent.com/assets/18320004/14388742/6986057c-fdea-11e5-9814-5a610684de0b.png">
      

     
     ### example
     ```
     "StringStylizer".stylize().font("Copperplate-Light").attr
     ```
     <img width="147" src="https://cloud.githubusercontent.com/assets/18320004/14388776/a274bf68-fdea-11e5-9634-840d0b5fdacb.png">
     

    /**
     The value of NSShadowAttributeName
     
     ### example
     ```
     let shadow = NSShadow()
     shadow.shadowOffset = CGSizeMake(1, 1)
     shadow.shadowColor = .redColor()
     shadow.shadowBlurRadius = 2
     "StringStylizer".stylize().shadow(shadow).attr
     ```
     <img width="138" alt="2016-04-10 18 35 27" src="https://cloud.githubusercontent.com/assets/18320004/14409343/ef91361c-ff4a-11e5-9c79-23e42a07ce81.png">
     
     - parameter value:NSShadow
     - returns: StringStylizer<Styling>
     */
