searchHelper
                    .getDocumentByDocId(docId, new String[] { fessConfig.getIndexFieldUrl(), fessConfig.getIndexFieldLang() },
                            OptionalThing.empty())
                    .ifPresent(doc -> {
                        final String favoriteUrl = DocumentUtil.getValue(doc, fessConfig.getIndexFieldUrl(), String.class);
                        final String userCode = userInfoHelper.getUserCode();

     * The value is, e.g. url <br>
     * comment: Field name for URL in the index.
     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     */
    String getIndexFieldUrl();

    /**
     * Get the value for the key 'index.field.doc_id'. <br>
     * The value is, e.g. doc_id <br>
     * comment: Field name for document ID in the index.