@Test
    public void testImmutableMap() throws BOSHException {
        try {
            AbstractBody body = createBody();
            assertNotNull("createBody returned null", body);
            Map<BodyQName, String> map = body.getAttributes();
            map.put(BodyQName.createBOSH("foo"), "bar");
            fail("Attributes map is not write-protected");
        } catch (Throwable thr) {
            // Good.
        }
    }