public ActionResult Refuel(int gasPumpIndex, int tapIndex, float liter)
        {
            // get selected gas pump
            GasPump gasPump = Context.GetGasStation().GetGasPumps()[gasPumpIndex];

            // get tap and call 'Fuel'
            Tap tap = gasPump.GetTaps()[tapIndex];

            gasPump.Fuel(tap, liter);

            return(RedirectToAction("Index", new { gasPumpIndex }));
        }
        public ActionResult SelectTap(int gasPumpIndex, int tapIndex)
        {
            // get selected gas pump
            GasPump gasPump = Context.GetGasStation().GetGasPumps()[gasPumpIndex];

            // get requested tap and call 'SelectTap'
            Tap tap = gasPump.GetTaps()[tapIndex];

            gasPump.SelectTap(tap);

            return(RedirectToAction("Index", new { gasPumpIndex }));
        }