Exceptions.java

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 {}
}

ExceptionsTest.java

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();
    }
}

gistfile1.txt

> java ExceptionsTest
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)