@Override
    public String uuid() {
        if (!guidService.dataPresent()) {
            guidService.store(UUID.randomUUID().toString());
        }
        return guidService.load();
    }
@Test
    public void shouldCreateGuidIfOneNotAlreadySet() throws Exception {
        guidService.delete();
        String guid = agentRegistry.uuid();
        assertNotNull(guid);
        assertThat(guid, is(agentRegistry.uuid()));
        assertThat(guid, is(not(GUID)));
    }