    @Test
    public void init_MulticastAddressNotProvided() throws Exception {


        Configuration c = new Configuration();
        assertNull(c.getInetAddress());

        MulticastSender s = getSenderToTest(c);

        try {

            s.init();
            fail("should have thrown exception");
        }
        catch(UserErrorException e) {

            String msg = e.getMessage();
            assertTrue(msg.contains("missing required multicast address"));
        }
    }