}

    String getIndexAdminRequiredFields();

    default boolean validateIndexRequiredFields(final Map<String, Object> source) {
        return invalidIndexRequiredFields(source).isEmpty();
    }

    default List<String> invalidIndexRequiredFields(final Map<String, Object> source) {
        final RequiredValidator requiredValidator = new RequiredValidator();

        final FessConfig fessConfig = ComponentUtil.getFessConfig();

        try {
            if (!fessConfig.validateIndexRequiredFields(doc)) {
                throwError.accept(messages -> fessConfig.invalidIndexRequiredFields(doc)
                        .stream()
                        .forEach(s -> messages.addErrorsPropertyRequired("doc." + s, s)));
            }

            if (!fessConfig.validateIndexArrayFields(doc)) {