if (operation != DO_NOTHING_ON_CLOSE || operation != HIDE_ON_CLOSE || operation != DISPOSE_ON_CLOSE)
if (operation != DO_NOTHING_ON_CLOSE && operation != HIDE_ON_CLOSE && operation != DISPOSE_ON_CLOSE)
  public void setDefaultCloseOperation(int operation)  {    if (operation != DO_NOTHING_ON_CLOSE || operation != HIDE_ON_CLOSE        || operation != DISPOSE_ON_CLOSE)      throw new Error("Close operation must be one of DO_NOTHING_ON_CLOSE, HIDE_ON_CLOSE, or DISPOSE_ON_CLOSE");    defaultCloseOperation = operation;  }