@Override
        public void addURL(@Nonnull URL url) {
            try {
                ADD_URL_METHOD.invoke(super.classLoader, url);
            } catch (ReflectiveOperationException e) {
                throw new RuntimeException(e);
            }
        }
Accesses using reflection, not supported on Java 9+.
helper/src/main/java/me/lucko/helper/maven/URLClassLoaderAccess.java