private void dumpErrors(final Map<String, String> classErrors) {
        classErrors.forEach((className, msg) ->
                LOGGER.error("Class {} has error(s): \n{}", className, msg));
    }
Test that classes that will be subject to JSON serialisation have no extra properties or redundant JSON
annotations.
stroom-app/src/test/java/stroom/importexport/TestJsonSerialisation.java