The following run-time exception is raised

    > Exception in thread "main" java.lang.IllegalAccessError:
    > failed to access class pkg.Exceptions$EBase from class ExceptionsTest
    > (pkg.Exceptions$EBase and ExceptionsTest are in unnamed module of loader 'app')
    > at ExceptionsTest.main(ExceptionsTest.java:8)

when running "java ExceptionsTest" program with

    > package pkg;
    > public class Exceptions {
    > private static class EBase extends Exception {
    > public void m() {}
    > }
    > public static class E1 extends EBase {}
    > public static class E2 extends EBase {}
    > }

and

    > import pkg.Exceptions;
    > public class ExceptionsTest {
    > public static void main(String[] args) {
    > try {
    > m1();
    > } catch (Exceptions.E1 | Exceptions.E2 e) {
    > e.m();
    > }
    > }
    > private static void m1() throws Exceptions.E1, Exceptions.E2 {
    > throw new Exceptions.E1();
    > }
    > }

Source(s):
- https://gist.github.com/DasBrain/61d2859a66183d29cb2eb9bf4cc1c81b
- https://twitter.com/lukaseder/status/1544713480024068098