接口继承接口的意义

interface a {
    void go();

    void act();
}

interface b extends a {
}

abstract class c implements b {

    public void go() {

    }

}

class d extends c {

    @Override
    public void go() {
        super.go();
    }

    /*
     * (non-Javadoc)
     * 
     * @see pac.testin.a#act()
     */
    public void act() {
        // TODO Auto-generated method stub

    }

}