private void refuelVehicle() { string licensePlate = getLicensePlate(); Fuel.eFuelType fuelType; float amountOfFuel; m_UserInterface.GetfuelType(out fuelType); Fuel fuel = m_Garage.ManageGarageDictionary[licensePlate].newVehicle.EnergySource as Fuel; if (m_Garage.ManageGarageDictionary[licensePlate].newVehicle.EnergySource is Fuel) { fuel.CheckFuelType(fuelType); } else { throw new ArgumentException("User try to refuel electric car"); } m_UserInterface.GetAmountOfFuel(out amountOfFuel); m_Garage.ManageGarageDictionary[licensePlate].newVehicle.EnergySource.FillEnergy(amountOfFuel); }