public static string GetBoxAttribute(string file, long boxId, ShieldBoxItem attribute)
        {
            XElement root = XElement.Load(file);

            XElement elem = root
              .Elements(ShieldBoxItem.ShieldBox.ToString())
              .Single(itemName => itemName.Attribute(ShieldBoxItem.BoxId.ToString()).Value == boxId.ToString());

            return elem.Attribute(attribute.ToString()).Value;
        } 
        public static void SetBoxAttribute(string file, long boxId, ShieldBoxItem attribute, string newValue)
        {
            XElement root = XElement.Load(file);

            XElement elem = root
                .Elements(ShieldBoxItem.ShieldBox.ToString())
                .Single(itemName => itemName.Attribute(ShieldBoxItem.BoxId.ToString()).Value == boxId.ToString());

            elem.Attribute(attribute.ToString()).Value = newValue;

            root.Save(file);
        }