//稿费收入税率是20%
public class RoyaltyIncome extends Income 
{

    //继承父类的构造方法    
    public RoyaltyIncome(double income) 
    {
        super(income);
    }

    //计算稿费税收 重写计算税收的方法    
    @Override    
    public double getTax() 
    {
        return this.income * 0.2;
    }
}