The `setSpeedX` was underlined for the error "not all code paths return a value". May I know how do I solve it? The codes are as below:

```
class Ball
{
    public int speedX { get; private set; }
    public int speedY { get; private set; }
    public int positionX { get; private set; }
    public int positionY { get; private set; }

    public Ball(int speedX, int speedY, int positionX, int positionY)
    {
        this.speedX = speedX;
        this.speedY = speedY;
        this.positionX = positionX;
        this.positionY = positionY;
    }

    public int setSpeedX(int newSpeedX)
    {
        speedX = newSpeedX;
    }    

    public int setSpeedY(int newSpeedY)
    {
        speedY = newSpeedY;
    }

    public int setPositionX(int newPositionX)
    {
        positionX = newPositionX;
    }

    public int setPositionY(int newPositionY)
    {
        positionY = newPositionY;
    }
}

```

Thank you.