}
        return fieldSet;
    }

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

    default List<String> invalidIndexDoubleFields(final Map<String, Object> source) {
        final DoubleTypeValidator doubleValidator = new DoubleTypeValidator();

            }
            if (!fessConfig.validateIndexDoubleFields(doc)) {
                throwError.accept(messages -> fessConfig.invalidIndexDoubleFields(doc)
                        .stream()
                        .forEach(s -> messages.addErrorsPropertyTypeDouble("doc." + s, s)));
            }
        } catch (final Exception e) {