public int addFuelToCar(int litresAdded) {
	        if(isCarRented() == false || getFuelInCar() == getFuelCapacity()){
				return 0;
			} else {
	        int fuelTotal = fuelInCar + litresAdded;
			int fuel = Math.min(fuelTotal, fuelCapacity);
			fuelInCar = fuel;
			if (litresAdded >= (fuelCapacity - fuelInCar)){
				return fuelCapacity - fuelInCar;
			} else {
			return litresAdded;
			}
		}
	  }