String url = "http://example.com/test";
        String message = "Outer error message";
        Exception innerCause = new IllegalArgumentException("Inner cause");
        Exception middleCause = new IllegalStateException("Middle cause", innerCause);
        Exception outerCause = new RuntimeException("Outer cause", middleCause);

        mixedMap.put(null, "test");
        assertEquals(228L, MemoryUtil.sizeOf(mixedMap));

        // Nested maps
        Map<String, Map<String, String>> nestedMap = new HashMap<>();
        nestedMap.put("outer", Maps.map("inner", "value").$());
        assertEquals(183L, MemoryUtil.sizeOf(nestedMap));
    }

    @Test
    public void test_sizeOf_customObjects() {

        innerBoolQueryBuilder.add(innerTermQuery, BooleanClause.Occur.MUST);
        BooleanQuery innerBooleanQuery = innerBoolQueryBuilder.build();

        // Create outer BooleanQuery
        BooleanQuery.Builder outerBoolQueryBuilder = new BooleanQuery.Builder();
        outerBoolQueryBuilder.add(innerBooleanQuery, BooleanClause.Occur.SHOULD);

        Exception innerException = new IllegalArgumentException("Invalid argument");
        Error middleError = new AssertionError("Assertion failed", innerException);
        RuntimeException outerException = new RuntimeException("Outer error", middleError);
        ThumbnailGenerationException exception = new ThumbnailGenerationException(message, outerException);

        assertEquals(message, exception.getMessage());

        final StringWriter stringWriter = new StringWriter();
        final PrintWriter writer = new PrintWriter(stringWriter);

        final Map<String, Object> nestedData = Map.of("outer", Map.of("inner", "value"));
        chatApiManager.sendSseEvent(writer, "test", nestedData);

        final String output = stringWriter.toString();
        assertTrue(output.contains("event: test"));