private void printStatistics() {
    // add statements into this method!
    System.out.println("****End of simulation report****");
    System.out.println("\t" + " have arrived         :" + totalArrival);
    System.out.println("\t" + " have gone away       :" + numGoAway);
    System.out.println("\t" + " have been served     :" + numServed);
    System.out.println("****Current gaspump info****");
    ;
    gasStationObj.printStatistics();

    System.out.println("\tTotal waiting time      : " + totalWaitingTime);
    System.out.println("\tAverage waiting time    : " + (totalWaitingTime / numServed));

    System.out.println("****Busy Gas Pump info****");
    while (!gasStationObj.emptyBusyGasPumpQ()) {
      GasPump tempgas = gasStationObj.removeBusyGasPumpQ();
      tempgas.printStatistics();
    }
    System.out.println("****Free Gas Pump Info****");
    while (!gasStationObj.emptyFreeGasPumpQ()) {
      GasPump tempgas1 = gasStationObj.removeFreeGasPumpQ();
      tempgas1.printStatistics();
    }
    // print out simulation results
    // see the given example in project statement
    // you need to display all free and busy tellers

  }