@Test
    void showPropsWithNullValues() {
        // list any config values that are null.  This may be valid so no assertions used.
        PropertyUtil.walkObjectTree(
                new ProxyConfig(),
                prop -> !prop.hasAnnotation(JsonIgnore.class),
                prop -> {
                    if (prop.getValueFromConfigObject() == null) {
                        LOGGER.warn("{} => {} is null",
                                prop.getParentObject().getClass().getSimpleName(),
                                prop.getName());
                    }
                });
    }
Test to verify that all fields in the config tree of type stroom.*
implement IsProxyConfig . Also useful for seeing the object tree
and the annotations
stroom-proxy/stroom-proxy-app/src/test/java/stroom/proxy/app/TestProxyConfig.java