*
     * @param field the field name to check
     * @return true if the field can be used for faceted search, false otherwise
     */
    public boolean isFacetField(final String field) {
        if (StringUtil.isBlank(field)) {
            return false;
        }
        return facetFieldSet != null && facetFieldSet.contains(field);
    }

    /**
     * Checks if the specified sort value is valid for facet sorting.

                }
                queryBuf.append(')');
            }
        }));

        final String baseQuery = queryBuf.toString().trim();
        if (StringUtil.isBlank(sortField)) {
            return baseQuery;
        }
        return baseQuery + " sort:" + sortField;
    }

    /**
     * Appends a query string to the query buffer with proper formatting.

            init();
        }

        final String virtualHostKey = ComponentUtil.getVirtualHostHelper().getVirtualHostKey();
        final List<LabelTypeItem> labelList;
        if (StringUtil.isBlank(virtualHostKey)) {
            labelList =
                    labelTypeItemList.stream().filter(item -> matchLocale(requestLocale, item.getLocale())).collect(Collectors.toList());
        } else {

                writeHeaders(response);
                final String responseContentType = curlResponse.getHeaderValue("Content-Type");
                if (StringUtil.isBlank(responseContentType)) {
                    response.setHeader("Content-Type", "application/json");
                } else {
                    response.setHeader("Content-Type", responseContentType);
                }

                if (resultsPerPage instanceof Integer) {
                    form.num = (Integer) resultsPerPage;
                }
            }
        }

        if (StringUtil.isBlank(form.q) && form.fields.isEmpty() && !form.hasConditionQuery()) {
            // redirect to index page
            form.q = null;
            return redirectToRoot();
        }

        try {

    }

    @Override
    public Integer getTimeToLive() {
        String value = getHandlerParameterMap().get("time_to_live");
        if (StringUtil.isBlank(value)) {
            value = getHandlerParameterMap().get("timeToLive"); // TODO remove
            if (StringUtil.isBlank(value)) {
                return null;
            }
            logger.warn("timeToLive is deprecated. Please use time_to_live.");
        }

    #  If you use synchronizer and specify this property, no need to refresh(F5) your eclipse project.
    #  The projectName can be set plural names by slash '/'. e.g. sea/land
    #
    #; refreshMap = map:{
    #    ; projectName = $$AutoDetect$$
    #    ; requestUrl = http://localhost:8386/
    #}
    # - - - - - - - - - -/

    public void addElevateWord(final String word, final String reading, final String[] tags, final String[] permissions, final Float boost,
            final boolean apply) {
        final String[] readings;
        if (StringUtil.isBlank(reading)) {
            readings = word.replace("　", TEXT_SEP).replaceAll(TEXT_SEP + "+", TEXT_SEP).split(TEXT_SEP);
        } else {

    protected boolean isEmptyArray(final String[] values) {
        if (values == null || values.length == 0) {
            return true;
        }
        return stream(values).get(stream -> stream.allMatch(StringUtil::isBlank));
    }

    /**
     * Simplifies the array.
     *
     * @param values The array.
     * @return The simplified array.
     */
    protected static String[] simplifyArray(final String[] values) {

        // Test with special numeric values
        OptionalEntity<Double> nanOpt = OptionalUtil.ofNullable(Double.NaN);
        assertTrue(nanOpt.isPresent());
        assertTrue(Double.isNaN(nanOpt.get()));

        OptionalEntity<Double> infinityOpt = OptionalUtil.ofNullable(Double.POSITIVE_INFINITY);
        assertTrue(infinityOpt.isPresent());
        assertTrue(Double.isInfinite(infinityOpt.get()));