final FessConfig fessConfig = ComponentUtil.getFessConfig();
        return searchEngineClient.deleteByQuery(fessConfig.getIndexDocumentUpdateIndex(),
                QueryBuilders.termQuery(fessConfig.getIndexFieldParentId(), id));
    }

    /**
     * Retrieves all child documents that belong to the specified parent document.
     *
     * @param searchEngineClient the search engine client to use for retrieval

                    fessConfig.getIndexFieldLang(), //
                    fessConfig.getIndexFieldLastModified(), //
                    fessConfig.getIndexFieldMimetype(), //
                    fessConfig.getIndexFieldParentId(), //
                    fessConfig.getIndexFieldPrimaryTerm(), //
                    fessConfig.getIndexFieldRole(), //
                    fessConfig.getIndexFieldSegment(), //

            parentUrl = pathMappingHelper.replaceUrl(sessionId, parentUrl);
            putResultDataBody(dataMap, fessConfig.getIndexFieldUrl(), parentUrl);
            putResultDataBody(dataMap, fessConfig.getIndexFieldParentId(), crawlingInfoHelper.generateId(dataMap));
            putResultDataBody(dataMap, fessConfig.getIndexFieldUrl(), url); // set again
        }
        // thumbnail

            parentUrl = pathMappingHelper.replaceUrl(sessionId, parentUrl);
            putResultDataBody(dataMap, fessConfig.getIndexFieldUrl(), parentUrl);
            putResultDataBody(dataMap, fessConfig.getIndexFieldParentId(), crawlingInfoHelper.generateId(dataMap));
            putResultDataBody(dataMap, fessConfig.getIndexFieldUrl(), url); // set again
        }
        // thumbnail

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

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