class Eatable{ var v;
   fcn eat{ println("munching ",self.topdog.name); }
}
class FoodBox{
   fcn init(food1,food2,etc){
      editable,garbage:=vm.arglist.filter22("isChildOf",Eatable);
      var contents=editable;
      if(garbage) println("Rejecting: ",garbage);
   }
}