public class Doubler{ public static int doubleMe(Holder h){  return h.getAmount()*2; }}and:public class Holder{  int amount=10;  public void doubleAmount() {   amount=Doubler.doubleMe(this);   }   public void getAmount(){ return amount; }  // more Code}
public class Doubler{ public static int doubleMe( [PLACE HERE] h){  return [PLACE HERE]*2; }}public class Holder{ int amount =10; public void doubleAmount(){  amount= Doubler.doubleMe([PLACE HERE]); } public int getAmount(){return amount;}; /*more code*/}