/// <summary>
 /// Retrieves a list of invoice number, item name, item number, cashier, date sold, price, quantity, and discount amounts for each item record
 /// </summary>
 /// <param name="startDateTime">The period start date/time</param>
 /// <param name="endDateTime">The period end date/time</param>
 /// <returns>A list of ItemSale objects</returns>
 public List <ItemSale> GetItemsSold(DateTime startDateTime, DateTime endDateTime)
 {
     using (var client = new SalesServiceClient())
     {
         client.Open();
         return(new List <ItemSale>(client.GetItemsSold(startDateTime, endDateTime)));
     }
 }
 /// <summary>
 /// Retrieves a list of invoice number, item name, item number, cashier, date sold, price, quantity, and discount amounts for each item record
 /// </summary>
 /// <param name="startDateTime">The period start date/time</param>
 /// <param name="endDateTime">The period end date/time</param>
 /// <returns>A list of ItemSale objects</returns>
 public List<ItemSale> GetItemsSold(DateTime startDateTime, DateTime endDateTime)
 {
     using (var client = new SalesServiceClient())
     {
         client.Open();
         return new List<ItemSale>(client.GetItemsSold(startDateTime, endDateTime));
     }
 }