public void Delete([FromBody] Wenslijst list)
        {
            var itemToRemove = this._context.Wenslijsten.Where(item => (item.klantId == list.klantId && item.productNmr == list.productNmr)).FirstOrDefault();

            this._context.Wenslijsten.Remove(itemToRemove);
            this._context.SaveChanges();
        }
        public void Post([FromBody] Wenslijst list)
        {
            var result = this._context.Wenslijsten.Where((w) => w.klantId == list.klantId && w.productNmr == list.productNmr).FirstOrDefault();

            if (result == null)
            {
                this._context.Wenslijsten.Add(list);
                this._context.SaveChanges();
            }
        }