// The exception should be serializable since it extends RuntimeException
        assertTrue(exception instanceof java.io.Serializable);
    }

    @Test
    public void test_getMessage_withComplexCause() {
        // Test getMessage behavior with complex cause structure
        final Exception innerCause = new NullPointerException("NPE occurred");

Shinsuke Sugaya <******@****.***> 1768120985 +0900