                 _value, options:opts, error:nil
             )
             return NSString(
-                data:data, encoding:NSUTF8StringEncoding
+                data:data!, encoding:NSUTF8StringEncoding
             )
         }
     }

        var err:NSError?
        let enc = NSUTF8StringEncoding
        var obj:AnyObject? = NSJSONSerialization.JSONObjectWithData(
            str.dataUsingEncoding(enc), options:nil, error:&err
        )
        return err != nil ? JSON(err!) : JSON(obj!)
    }

            return self
        case let ary as NSArray:
            if 0 <= idx && idx < ary.count {
                return JSON(ary[idx])
            }
            return JSON(NSError(
                domain:"JSONErrorDomain", code:404, userInfo:[
