@Test
    public void test_assistCurrentDBDef() {
        DBDef result = invokerAssistant.assistCurrentDBDef();
        assertNull(result);
    }

    // Test assistDataSource
    @Test
    public void test_assistDataSource() {
        DataSource result = invokerAssistant.assistDataSource();
        assertNull(result);
    }

    // Test assistDBMetaProvider
    @Test
    public void test_assistDBMetaProvider() {

        assertNull(languageHelper.getSupportedLanguage("fr"));
        assertNull(languageHelper.getSupportedLanguage("de"));
        assertNull(languageHelper.getSupportedLanguage("unknown"));
    }

    @Test
    public void test_getSupportedLanguage_blank() {
        assertNull(languageHelper.getSupportedLanguage(null));
        assertNull(languageHelper.getSupportedLanguage(""));

        // These should return null
        assertNull(freshData.getDocumentItems());
        assertNull(freshData.getFacetResponse());
        assertNull(freshData.getAppendHighlightParams());
        assertNull(freshData.getExecTime());
        assertNull(freshData.getAllRecordCountRelation());
        assertNull(freshData.getPageNumberList());
        assertNull(freshData.getSearchQuery());

        assertNull(exception.getMessage());
        assertNull(exception.getCause());
        assertTrue(exception instanceof FessSystemException);
    }

    @Test
    public void test_constructorWithNullCause() {
        // Test constructor with null cause
        SearchQueryException exception = new SearchQueryException((Throwable) null);

        assertNull(exception.getCause());

        String type = null;
        String message = null;
        InvalidAccessTokenException exception = new InvalidAccessTokenException(type, message);

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

    @Test
    public void test_constructor_withEmptyType() {
        // Test constructor with empty type string
        String type = "";

        // Verify
        assertNotNull(exception);
        assertNull(exception.getMessage());
        assertNull(exception.getCause());
        assertNull(exception.getMessageCode());
    }

    @Test
    public void test_constructor_twoParametersWithNullMessageCode() {
        // Setup
        final String message = "Test message";

        // Execute

                    return null;
                }
                return createMockRescorerBuilder();
            }
        };

        assertNull(queryRescorer.evaluate(Collections.emptyMap()));
        assertNull(queryRescorer.evaluate(new HashMap<>()));
    }

    @Test
    public void test_evaluate_withParams() {
        // Test implementation that returns a RescorerBuilder

        // Verify
        assertNotNull(exception);
        assertNull(exception.getMessage());
        assertNull(exception.getCause());
        assertNull(exception.getMessageCode());
    }

    @Test
    public void test_constructor_twoParametersWithNullMessageCode() {
        // Setup
        final String message = "Query error without message code";

    @Test
    public void test_getValue_with_null_map() {
        assertNull(DocumentUtil.getValue(null, "key", String.class));
        assertNull(DocumentUtil.getValue(null, "key", Integer.class));
    }

    @Test
    public void test_getValue_with_null_key() {
        Map<String, Object> doc = new HashMap<>();
        doc.put("key", "value");
        assertNull(DocumentUtil.getValue(doc, null, String.class));

        assertNull(result.getQuery());
        assertEquals("summary request", result.getReasoning());
    }

    @Test
    public void test_summary_withNullDocumentUrl() {
        final IntentDetectionResult result = IntentDetectionResult.summary(null, "no doc url");

        assertEquals(ChatIntent.SUMMARY, result.getIntent());
        assertNull(result.getDocumentUrl());
    }

    @Test