final StringBuilder textBuilder = new StringBuilder();

        // Add headers to text
        if (headers != null) {
            textBuilder.append(String.join(fieldSeparator, headers)).append(lineSeparator);
        }

        // Add rows to text
        for (final String[] row : rows) {
            if (headers != null && headers.length > 0) {

        verify(out, timeout(1000)).write(payload, 0, 3);

        // Stop the thread by sending n = -1
        synchronized (w) {
            w.write(new byte[0], -1, out);
        }

        w.join(2000);
        assertFalse(w.isAlive(), "WriterThread should stop after -1 sentinel");
    }

    @Test
    @DisplayName("WriterThread surfaces SmbException via checkException")

class StringUtilTest {

    @Test
    @DisplayName("Should join single element without delimiter")
    void testJoinSingleElement() {
        String result = StringUtil.join(",", "hello");
        assertEquals("hello", result);
    }

    @Test
    @DisplayName("Should join two elements with delimiter")
    void testJoinTwoElements() {
        String result = StringUtil.join(",", "hello", "world");

                }
            });
            threads[i].start();
        }

        // Wait for all threads to complete
        for (Thread thread : threads) {
            thread.join();
        }

        // Verify all entries were added
        assertEquals(1000, entry.getChildren().size());
    }

            // Non-critical failures - should NOT open circuit
            for (int i = 0; i < 5; i++) {
                try {
                    customCb.executeWithCircuitBreaker(() -> {
                        throw new RuntimeException("non-critical error");
                    }, isFailure);
                    fail("Should have thrown exception");

                return StringUtils.join(newInputs, ",");
            }
            return StringUtils.join(newInputs, ",") + "=>" + StringUtils.join(newOutputs, ",");
        }
        if (Arrays.equals(inputs, outputs)) {
            return StringUtils.join(inputs, ",");
        }
        return StringUtils.join(inputs, ",") + "=>" + StringUtils.join(outputs, ",");
    }

        }
        setAccessResultData(accessResultData);
    }

    /*
     * (non-Javadoc)
     *
     * @see org.codelibs.fess.crawler.entity.AccessResult#getId()
     */
    @Override
    public IDTYPE getId() {
        return id;
    }

    /*
     * (non-Javadoc)
     *
     * @see org.codelibs.fess.crawler.entity.AccessResult#setId(IDTYPE)
     */
    @Override

                    done.set(true);
                }
            }, Thread.currentThread().getName() + "-pdf");
            task.setDaemon(isDaemonThread);
            task.start();
            task.join(timeout);
            if (!done.get()) {
                for (int i = 0; i < 100 && !done.get(); i++) {
                    task.interrupt();
                    ThreadUtil.sleep(100L);
                }

    }

    /**
     * Test factory with non-AutoCloseable component type
     */
    public void test_destroyObject_nonAutoCloseable() throws Exception {
        TestComponent component = new TestComponent();
        PooledObject<TestComponent> pooledObject = new DefaultPooledObject<>(component);

        // Should not throw exception for non-AutoCloseable
        factory.destroyObject(pooledObject);

     */
    private StringUtil() {
    }

    /**
     * Implementation of {@link java.lang.String#join} backported for JDK7.
     *
     * @param delimiter the separator to use between elements
     * @param elements the elements to join
     * @return elements separated by delimiter
     */
    public static String join(final CharSequence delimiter, final CharSequence... elements) {
        final StringBuilder sb = new StringBuilder();