在自定义异常里面，在有参的构造方法中会有这么一句super(message);举个例子，public class NoexistException extends Exception { public NoexistException () {}; public NoexistException (String message) {                     super(message); }}我发现，我去掉super(message);程序运行的结果没什么不一样啊。public static void warn() throws NoexistException {  throw new NoexistException("图书不存在！"); } 求大神解答