//TODO: Mapper library like AutoMapper
        #region Mapper

        private static Item Map(PersistenceItem item)
        {
            if (item == null)
            {
                return(null);
            }

            return(new Item
            {
                Id = item.Id,
                Name = item.Name,
                Cost = item.Cost
            });
        }
        public Item CreateItem(Item item)
        {
            if (item == null)
            {
                return(null);
            }
            var insertItem = new PersistenceItem {
                Name = item.Name, Cost = item.Cost
            };

            var result = _dataContext.Items.Add(insertItem);

            _dataContext.SaveChanges();

            return(Map(result));
        }