class Methods {
    mt4(a,b,c) { return a.add(b).sub(c) ; }

    mt1(a) {return a;}

    mt2(a) {return a.f; }

    mt3(a) {return a.add();  }
}

class Test {
    java.lang.Object f;
    add(){}
    add(b){return b;}
    sub(b){}
}