@Override
  public void stop() {
    synchronized (getLock()) {
      if (myStopped) {
        throwInvalidState("Attempt to stop ProgressIndicator which is already stopped");
      }
      if (!myRunning) {
        throwInvalidState("stop() should be called only if start() called before");
      }
      myRunning = false;
      myStopped = true;
      stopSystemActivity();
    }
  }
@Override
  public void stop()