}

    protected void registerSpecifiedProperty(String propertyName) { // basically called by modified property registration
        if (__specifiedProperties != null) { // normally false, true if e.g. setting after selected
            __specifiedProperties.addPropertyName(propertyName);
        }
    }

    // ===================================================================================

        final List<? extends RESULT> list = delegateSelectList(cb, entityType);
        if (list.isEmpty()) {
            return null;
        }
        if (list.size() >= 2) {
            String msg = "The size of selected list is over 1: " + list.size();
            throw new FetchingOverSafetySizeException(msg, 1); // immediately caught by caller and translated
        }
        return list.get(0);
    }

    @Override

            if (logger.isDebugEnabled()) {
                logger.debug("Deleted {} documents. The execution time is {}ms.", sessionId,
                        (systemHelper.getCurrentTimeAsLong() - execTime2));
            }
        }
        finishedSessionIdList.clear();

        if (logger.isInfoEnabled()) {

                    // updated file
                    addDocument(localParams, dataMap);
                } else if (getParamValue(localParams, "event.delete", "delete").equals(eventType)) {
                    // deleted file
                    deleteDocument(localParams, dataMap);
                } else {
                    logger.warn("unknown event: {}, data: {}", eventType, dataMap);
                }
            } finally {

    }

    protected void registerSpecifiedProperty(String propertyName) { // basically called by modified property registration
        if (__specifiedProperties != null) { // normally false, true if e.g. setting after selected
            __specifiedProperties.addPropertyName(propertyName);
        }
    }

    // ===================================================================================

                final File propFile = ComponentUtil.getSystemHelper().createTempFile("crawler_", ".properties");
                if (propFile.delete() && logger.isDebugEnabled()) {
                    logger.debug("Deleted a temp file: {}", propFile.getAbsolutePath());
                }
                systemProperties.reload(propFile.getAbsolutePath());
                propFile.deleteOnExit();
            } catch (final Exception e) {

        final List<? extends RESULT> list = delegateSelectList(cb, entityType);
        if (list.isEmpty()) {
            return null;
        }
        if (list.size() >= 2) {
            String msg = "The size of selected list is over 1: " + list.size();
            throw new FetchingOverSafetySizeException(msg, 1); // immediately caught by caller and translated
        }
        return list.get(0);
    }

    @Override

                final File propFile = ComponentUtil.getSystemHelper().createTempFile("suggest_", ".properties");
                if (propFile.delete() && logger.isDebugEnabled()) {
                    logger.debug("Deleted a temp file: {}", propFile.getAbsolutePath());
                }
                systemProperties.reload(propFile.getAbsolutePath());
                propFile.deleteOnExit();
            } catch (final Exception e) {

            synchronized (searchEngineClient) {
                final long deletedDocCount = deleteOldDocuments(searchEngineClient, docList);
                if (logger.isDebugEnabled()) {
                    logger.debug("Deleted {} old docs", deletedDocCount);
                }
                searchEngineClient.addAll(fessConfig.getIndexDocumentUpdateIndex(), docList, (doc, builder) -> {

    }

    protected void registerSpecifiedProperty(String propertyName) { // basically called by modified property registration
        if (__specifiedProperties != null) { // normally false, true if e.g. setting after selected
            __specifiedProperties.addPropertyName(propertyName);
        }
    }

    // ===================================================================================