startLatch.countDown(); // Start all threads simultaneously
                assertTrue("Concurrent registration timed out", endLatch.await(10, TimeUnit.SECONDS));

                // Verify all searchers were registered (1 initial + numThreads * searchersPerThread)
                assertEquals(numThreads * searchersPerThread, registeredCount.get());

            } finally {
                executor.shutdown();

        }

    }

    /**
     * Returns the OpenSearch QueryBuilder for geographic queries.
     *
     * @return the QueryBuilder containing geo-distance queries, or null if no valid geo parameters were found
     */
    public QueryBuilder toQueryBuilder() {
        return builder;
    }

        String result1 = purgeDocJob.execute();

        // Reset the flag
        deleteByQueryCalled = false;

        String result2 = purgeDocJob.execute();

        // Assert both executions were successful
        assertEquals("", result1);
        assertEquals("", result2);
        assertTrue(deleteByQueryCalled);
    }

    @Test
    public void test_execute_withEmptyIndexName() {

                }
            }
            return null;
        }

        /**
         * Closes the updater and finalizes the file update operation.
         * If changes were committed, the temporary file replaces the original.
         * Otherwise, the temporary file is deleted.
         */
        @Override
        public void close() {
            try {
                writer.flush();

        /** Indicates that an exception occurred during URL access. */
        ACCESS_EXCEPTION,
        /** Indicates that a child URL was discovered. */
        CHILD_URL,
        /** Indicates that multiple child URLs were discovered. */
        CHILD_URLS,
        /** Indicates that a URL was evaluated for crawling eligibility. */
        EVALUATED,
        /** Indicates that a general exception occurred during processing. */

                    deleteOldDocs();
                }
            }
        }

        /**
         * Deletes old documents from the search index.
         * This method removes documents that were indexed in previous
         * crawling sessions for the same data configuration, keeping
         * only the documents from the current session.
         *
         * <p>The deletion process:</p>
         * <ul>

        // Each creates 2 indices (backup + rebuild) = 4 creates
        assertEquals("Only fess_config indices should be rebuilt", 4, testClient.createdIndices.size());
        // Verify no user/log indices were touched
        for (final String index : testClient.createdIndices) {
            assertFalse(index.contains("fess_user"), "fess_user should not be rebuilt");

     * restored. This provides a seamless user experience after authentication.
     *
     * @return Optional HtmlResponse containing the redirect to search page with parameters,
     *         or empty if no search parameters were found
     */
    protected OptionalThing<HtmlResponse> redirectToSearchPage() {
        final RequestParameter[] searchParameters = searchHelper.getSearchParameters();
        if (searchParameters.length > 0) {

     * This cache is refreshed periodically based on the lastLoadedTime.
     */
    protected volatile String[] dataStoreNames = StringUtil.EMPTY_STRINGS;

    /**
     * Timestamp of the last time data store names were loaded from plugin files.
     * Used to implement a time-based cache refresh mechanism.
     * Volatile to ensure visibility across threads.
     */
    protected volatile long lastLoadedTime = 0;

    /**

     */
    public OptionalEntity<WebConfig> getWebConfig() {
        return OptionalUtil.ofNullable(webConfig);
    }

    /**
     * Gets the file crawling configuration generated from the parsed GSA config.
     *
     * @return an optional containing the file configuration, or empty if no file URLs were found
     */