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)      close_action = operation;    else      // accept illegal value and set the property to the default value,      // that's what the reference implementation does      close_action = DO_NOTHING_ON_CLOSE;  }