// title
        // content
        // cache
        // digest
        // host
        // site
        // url
        // anchor
        // content_length
        // last_modified
        // id
        // virtual_host
        defaultDataMap.put(fessConfig.getIndexFieldVirtualHost(),

            public String getIndexFieldHost() {
                return "host";
            }

            @Override
            public String getIndexFieldLastModified() {
                return "last_modified";
            }

            @Override
            public String getIndexFieldMimetype() {
                return "mimetype";
            }

            @Override

            public String getIndexFieldSite() {
                return "site";
            }

            @Override
            public String getIndexFieldLastModified() {
                return "last_modified";
            }

            @Override
            public String getIndexFieldTimestamp() {
                return "timestamp";
            }

            @Override

                    return "lang";
                case FessConfig.INDEX_FIELD_has_cache:
                    return "has_cache";
                case FessConfig.INDEX_FIELD_last_modified:
                    return "last_modified";
                case FessConfig.INDEX_FIELD_ANCHOR:
                    return "anchor";
                case FessConfig.INDEX_FIELD_SEGMENT:
                    return "segment";

                return "lang,role,label,anchor,virtual_host";
            }

            @Override
            public String getIndexAdminDateFields() {
                return "expires,created,timestamp,last_modified";
            }

            @Override
            public String getIndexAdminIntegerFields() {
                return "";
            }

            @Override

                                    <div class="col-sm-9">
                                        <la:errors property="doc.last_modified"/>
                                        <la:text styleId="doc.last_modified"
                                                 property="doc.last_modified" styleClass="form-control"

            public String getIndexFieldSite() {
                return "site";
            }

            @Override
            public String getIndexFieldLastModified() {
                return "last_modified";
            }

            @Override
            public String getIndexFieldTimestamp() {
                return "timestamp";
            }

            @Override

            public String getIndexFieldSite() {
                return "site";
            }

            @Override
            public String getIndexFieldLastModified() {
                return "last_modified";
            }

            @Override
            public String getIndexFieldTimestamp() {
                return "timestamp";
            }

            @Override

                        host:
                          type: string
                          format: hostname
                          example: "fess.codelibs.org"
                        last_modified:
                          type: string
                          format: date-time
                          example: "2017-10-09T22:28:56.000Z"
                        content_length:

                Set.of(), //
                "{\"timestamp\":{\"order\":\"desc\"}}{\"last_modified\":{\"order\":\"asc\"}}", //
                buildQuery("sort:timestamp.desc sort:last_modified"));
        assertQueryContext(query, Map.of(), //
                Set.of(), //
                "{\"timestamp\":{\"order\":\"desc\"}}{\"last_modified\":{\"order\":\"desc\"}}", //
                buildQuery("sort:timestamp.desc sort:last_modified.desc"));