@Test
   public void testEmptyPathImmutable() throws Exception {

	DistinguishedName emptyPath = DistinguishedName.EMPTY_PATH;
	try {
		emptyPath.add("cn=John Doe");
		fail("UnsupportedOperationException expected");
	}
	catch (UnsupportedOperationException expected) {
		assertThat(true).isTrue();
	}
}