@Override
            public String getIndexAdminRequiredFields() {
                return "url,title,role,boost";
            }

            @Override
            public String getIndexAdminArrayFields() {
                return "lang,role,label,anchor,virtual_host";
            }

            @Override
            public String getIndexAdminDateFields() {

        }
        return list;
    }

    String getIndexAdminArrayFields();

    default Set<String> getIndexAdminArrayFieldSet() {
        @SuppressWarnings("unchecked")
        Set<String> fieldSet = (Set<String>) propMap.get(INDEX_ADMIN_ARRAY_FIELD_SET);
        if (fieldSet == null) {
            fieldSet = split(getIndexAdminArrayFields(), ",")

     * comment: Array-type fields for admin in the index.
     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     */
    String getIndexAdminArrayFields();

    /**
     * Get the value for the key 'index.admin.date.fields'. <br>
     * The value is, e.g. expires,created,timestamp,last_modified <br>
     * comment: Date-type fields for admin in the index.