public static ReturnItem WithWeeeCategory(WeeeCategory category)
            {
                var builder = new ReturnItemBuilder();
                builder.weeeCategory = category;

                return builder.Build();
            }
            public static ReturnItem WithTonnage(decimal tonnage)
            {
                var builder = new ReturnItemBuilder();
                builder.tonnage = tonnage;

                return builder.Build();
            }
            public static ReturnItem WithObligationType(ObligationType obligationType)
            {
                var builder = new ReturnItemBuilder();
                builder.obligationType = obligationType;

                return builder.Build();
            }