         
     }
     override var description : String {
-        let keys = ["access_token","expires_in","uid","avatar_large","name"]
+        let keys = ["access_token","expires_in","uid","avatar_large","name","expires_date"]
     return dictionaryWithValuesForKeys(keys).description
     }
     //归档

    class func loadAccount() ->useAccount?{
        let path = (NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true).last! as NSString).stringByAppendingPathComponent("account.plist")
        if let account = NSKeyedUnarchiver.unarchiveObjectWithFile(path) as? useAccount {
        return account
        }
        return nil
    }

        uid = aDecoder.decodeObjectForKey("uid") as? String
        avatar_large = aDecoder.decodeObjectForKey("avatar_large") as? String
        name = aDecoder.decodeObjectForKey("name") as? String
        expires_date = aDecoder.decodeObjectForKey("expires_date") as? NSDate
        
    }
    //归档
