ios - Swift: result["data"] always returns nil while I fetch data from Facebook using FBSDK 4.x -

i trying fetch albums photo facebook using fbsdk 4.x, , result json. try access properties 'result?["data"]', , always return nil. see below code:

    func fetchalbum(){     print(fbsdkaccesstoken.currentaccesstoken())     let graphrequest: fbsdkgraphrequest = fbsdkgraphrequest(graphpath: "me?fields=albums", parameters: nil);     graphrequest.startwithcompletionhandler({ (connection, result, error) -> void in         if let goterror = error{             println(goterror.description);         }         else{             print("fetched data: \(result)")                         if let graphdata = result["data"] as? [fbsdkshareopengraphobject]{                  var albums:[albummodel] =  [albummodel]();                 obj:fbsdkshareopengraphobject in graphdata {                 let desc = obj.description;                 print(desc);                 let name = obj.valueforkey("name") as! string;                 print(name);                 if(name == "etc"){                     let test="";                 }                 let id = obj.valueforkey("id") as! string;                 var cover = "";                 if let existscoverphoto : anyobject = obj.valueforkey("cover_photo"){                     let coverlink = existscoverphoto as! string;                     cover = "/\(coverlink)/photos";                 }                 //print(coverlink);                 let link = "/\(id)/photos";                 let model = albummodel(name: name, link: link, cover:cover);                 albums.append(model);                 }             nsnotificationcenter.defaultcenter().postnotificationname("albumnotification", object: nil, userinfo: ["data":albums]);                  }else{                     print("--------------------------")             }          }     }) } 

by code above me?