@Override
  public final void checkCanceled() {
    ProgressWrapper current = this;
    while (true) {
      if (current.isCanceledRaw()) {
        current.checkCanceledRaw();
      }
      ProgressIndicator original = current.getOriginalProgressIndicator();
      if (original instanceof ProgressWrapper) {
        current = (ProgressWrapper)original;
      }
      else {
        original.checkCanceled();
        break;
      }
    }
  }
@Override
  public final void checkCanceled()