public static void Save()
    {
            var model = ProtoBuf.Meta.TypeModel.Create();

            AddTypeToModel<Staff>( model );
            AddTypeToModel<Hammer>( model );
            AddTypeToModel<SmallBundle>( model );
            AddTypeToModel<CultureInfo>( model );

            MetaType weapon = AddTypeToModel<Weapon>( model );
            weapon.AddSubType( 100, typeof( Staff ) );
            weapon.AddSubType( 101, typeof( Hammer ) );
            weapon.AddSubType( 102, typeof( SmallBundle ) );

            MetaType item = AddTypeToModel<Item>( model );
            item.AddSubType( 100, typeof( Weapon ) );

            List<Staff> weapons = _items.OfType<Staff>().ToList<Staff>();

            Serialize( model, weapons );
        }

        private static MetaType AddTypeToModel<T>(RuntimeTypeModel typeModel)
        {
            var properties = typeof(T).GetProperties().Select(p => p.Name).OrderBy(name => name);
            return typeModel.Add(typeof(T), true).Add(properties.ToArray());
        }