entity.put(fessConfig.getIndexFieldDocId(), systemHelper.generateDocId(entity));
            return OptionalEntity.of(entity);
        case CrudMode.EDIT:
            final String docId;
            if (form.doc != null) {
                docId = (String) form.doc.get(fessConfig.getIndexFieldDocId());
            } else {
                docId = null;
            }

            final List<Map<String, Object>> docList = searchHelper.getDocumentListByDocIds(docIds, new String[] {
                    fessConfig.getIndexFieldUrl(), fessConfig.getIndexFieldDocId(), fessConfig.getIndexFieldFavoriteCount() },
                    OptionalThing.empty(), SearchRequestType.JSON);
            List<String> urlList = new ArrayList<>(docList.size());

                        searchHelper
                                .getDocumentListByDocIds(clickCountMap.keySet().toArray(new String[clickCountMap.size()]),
                                        new String[] { fessConfig.getIndexFieldDocId(), fessConfig.getIndexFieldLang() },
                                        OptionalThing.of(FessUserBean.empty()), SearchRequestType.ADMIN_SEARCH)
                                .stream()

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

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