}
            final CrawlingConfigHelper crawlingConfigHelper = ComponentUtil.getCrawlingConfigHelper();
            synchronized (searchEngineClient) {
                final long deletedDocCount = deleteOldDocuments(searchEngineClient, docList);
                if (logger.isDebugEnabled()) {
                    logger.debug("Deleted {} stale documents", deletedDocCount);
                }

            }
        };
        ComponentUtil.register(client, "searchEngineClient");
        final DocList docList = new DocList();
        assertEquals(0, indexingHelper.deleteOldDocuments(client, docList));
        assertEquals(0, docList.size());
        assertEquals(0, deletedDocIdList.size());

        docList.clear();
        deletedDocIdList.clear();