public <ConfigType extends ConfigInstance> ConfigType toInstance(Class<ConfigType> clazz, String configId) {
        return ConfigInstanceUtil.getNewInstance(clazz, configId, this);
    }
@Test
    public void test_simple_map() {
        Slime slime = new Slime();
        Cursor map = slime.setObject().setObject("stringmap");
        map.setString("key","val");

        MaptypesConfig config = new ConfigPayload(slime).toInstance(MaptypesConfig.class, "");
        assertThat(config.stringmap("key"), is("val"));
    }