internal CSlot(int slotNo)
 {
     SlotNo   = slotNo;
     Coffee   = new NullCoffee();
     IsFilled = false;
     Status   = "";
 }
 internal void Finish()
 {
     if (Coffee is null)
     {
         return;
     }
     FunctionalList.PreparedCoffee.Add(Coffee);
     Coffee   = new NullCoffee();
     IsFilled = false;
 }