notifyObservers(RUN_FAILED);
  public void setRunning(boolean running) {    try {      createAllNodes();      createAllNodeViews();      startNodes();      isRunning = running;    } catch(IllegalStateException ise) {      JOptionPane.showMessageDialog(null, ("Cannot start run,  " + ise.getMessage()),                                    "Cannot start run",JOptionPane.ERROR_MESSAGE);    }    setChanged();    notifyObservers(TOGGLE_RUNNING_STATE);  }