public void doBackLog(){
        while (backLog.size()>0 && this.stock > 0){
            Customer c= this.backLog.removeFirst();
            if (this.stock < c.getJumMobil()){
                this.deStock(this.stock);
                c.setJumMobil(c.getJumMobil()-this.stock);
                this.backLog.addFirst(c);
            }
            else {
                this.deStock(c.getJumMobil());
            }
            //System.out.println("C-"+c.getName()+" do backLog:"+(c.getJumMobil()));
        }
    }