assertNotNull(results);
        // With multiple languages, should use ReadingConverterChain
    }

    @Test
    public void testConvertWithEmptyText() throws IOException {
        // Test convert with empty text
        String text = "";
        String field = "content";

        List<String> results = converter.convert(text, field, "en");

        assertNotNull(results);

        urlFilter.init(sessionId);
        // Initialization should complete without errors
        assertNotNull(urlFilter);
    }

    /**
     * Test initialization with null session ID
     */
    public void test_init_withNullSessionId() {
        urlFilter.init(null);
        // Should handle null session ID gracefully
        assertNotNull(urlFilter);
    }

    /**
     * Test initialization with empty session ID
     */

        String id = SuggestUtil.createSuggestTextId(text);
        assertNotNull(id);
        assertEquals(Base64.getEncoder().encodeToString(text.getBytes(CoreLibConstants.CHARSET_UTF_8)), id);

        // Test empty text
        String emptyText = "";
        String emptyId = SuggestUtil.createSuggestTextId(emptyText);
        assertNotNull(emptyId);

        }
    }

    public void test_parseLastModified() {
        final String value = "Mon, 01 Jun 2009 21:02:45 GMT";
        final Date date = httpClient.parseLastModifiedDate(value);
        assertNotNull(date);
    }

    public void test_processRobotsTxt() {
        final CrawlerWebServer server = new CrawlerWebServer(7070);
        server.start();

        final String url = "http://localhost:7070/hoge.html";

        final Suggester suggester = Suggester.builder().build(runner.client(), id);

        assertNotNull(suggester);
        assertNotNull(suggester.client);
        assertNotNull(suggester.indexer());
        assertNotNull(suggester.getNormalizer());
        assertNotNull(suggester.getReadingConverter());
        assertNotNull(suggester.settings());
        assertTrue(!Strings.isNullOrEmpty(suggester.index));
    }

        client = clientFactory.getClient(url);
        assertNotNull(client);
        assertTrue(client instanceof FileSystemClient);

        url = "smb:/home/hoge";
        client = clientFactory.getClient(url);
        assertNotNull(client);
        assertTrue(client instanceof SmbClient);

        url = "smb1:/home/hoge";
        client = clientFactory.getClient(url);
        assertNotNull(client);

        assertNotNull(exception);
        assertNull(exception.getMessage());
        assertNull(exception.getCause());
    }

    /**
     * Test constructor with empty message
     */
    public void test_constructor_withEmptyMessage() {
        CrawlerSystemException exception = new CrawlerSystemException("");

        assertNotNull(exception);

        assertNotNull(tokensContent);
        assertEquals(2, tokensContent.size());

        List<AnalyzeToken> tokensTitle = analyzer.analyze(text, "title", lang);
        assertNotNull(tokensTitle);
        assertEquals(2, tokensTitle.size());

        // Test with null field
        List<AnalyzeToken> tokensNull = analyzer.analyze(text, null, lang);
        assertNotNull(tokensNull);
        assertEquals(2, tokensNull.size());

        assertNotNull(item);
        assertEquals("text", item.getText());
        assertArrayEquals(readings, item.getReadings());
        assertNotNull(item.getFields());
        assertEquals(0, item.getFields().length);
        assertNotNull(item.getTags());
        assertEquals(0, item.getTags().length);
        assertNotNull(item.getRoles());

        String field = "content";

        List<String> readings1 = converter1.convert(text, field, "en");
        List<String> readings2 = converter2.convert(text, field, "ja");

        assertNotNull(readings1);
        assertNotNull(readings2);
        assertEquals("TEST", readings1.get(0));
        assertEquals("TEST", readings2.get(0));
    }

    @Test