练习继承和重写，但是在main class里没有把参数实例加进去

Question

public class HeliDemo 
{ 
public static void main (String[] args) 
{ 
Helicopter myHeli = new Helicopter(); 
myHeli.setColour("Red"); 
myHeli.setMaxSpeed(200); 
myHeli.vehicleDetails(); 
} 
}

class Vehcile{

    public String setColour(String colourString){
        return colourString;
    }
    public int setMaxSpeed(int MaxSpeed){
        return MaxSpeed;
    }
}

class Helicopter extends Vehcile{

    String colourString;
    int MaxSpeed;
    public String setColour(String colourString){
        return colourString;
    }
    public int setMaxSpeed(int MaxSpeed){
        return MaxSpeed;
    }
    public void vehicleDetails(){
        System.out.println("Vehicle Colour is " + colourString + " and " + "Max speed is "+ MaxSpeed);
    }

}

期望结果是：

实际结果：

Answer 1