throw new IllegalArgumentException();
throw new IllegalArgumentException(titleJustification + " is not a valid title justification.");
  public void setTitleJustification(int titleJustification)  {    if ((titleJustification < DEFAULT_JUSTIFICATION)        || (titleJustification > TRAILING))      throw new IllegalArgumentException();    // Swing borders are not JavaBeans, thus no need to fire an event.    this.titleJustification = titleJustification;  }