@Override
    public void addClient(int arrivingTime) {
        Random rand = new Random();
        int waitingTime = 0;
        Client newClient = ClientFactory.createClient(arrivingTime);
        for(Client c : clients){
            waitingTime += c.getServiceTime();
        }
        
        totalServiceTime += newClient.getServiceTime();
        totalWaitingTime += waitingTime;
        totalClientNumber ++;
        
        newClient.setWaitingTime(waitingTime);
        clients.add(newClient);
    }