    @Test
    public void testNoAnswer() throws Exception {

        dir1.donotAnswer = true;
        dir2.donotAnswer = true;

        try {
            DIRClient client = new DIRClient(testEnv.getDirClient(), servers, 5, 2);
            client.xtreemfs_address_mappings_get(null, RPCAuthentication.authNone, RPCAuthentication.userService, "*");
            fail("Expected exception.");
        } catch (IOException ex) {

        }
    }