关于extends的一个小问题

package Object;

public class Detergent extends Cleanser{
    public void scrub()
    {
        append("Detegent.scurb()");
        super.scrub();
    }

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Detergent x = new Detergent();
        x.dilute();
        x.scrub();
        System.out.println(x);
        System.out.println("askjdjasdljal");
        Cleanser.main(args);
    }

}
class Cleanser
{
    private String s = "Cleanser";
    public void append(String a)
    {
        s = s+a;
    }
    public void dilute()
    {
        append("dilute()");
    }
    public void scrub()
    {
        append("scurb()");
    }
    public String toString()
    {
        return s;
    }
    public static void main(String[] args)
    {
        Cleanser x = new Cleanser();
        x.dilute();
        x.scrub();
        System.out.println(x);
    }
}