assertNotNull(exception.getStackTrace());
        assertTrue(exception.getStackTrace().length > 0);
        assertNull(exception.getCause());
    }

    public void test_inheritance() {
        // Test that ResultOffsetExceededException is a subclass of FessSystemException
        ResultOffsetExceededException exception = new ResultOffsetExceededException("Test message");

            assertEquals("Serialization test", e.getMessage());
        } catch (Exception e) {
            fail("Should have caught DataStoreException");
        }
    }

    public void test_inheritance() {
        // Test inheritance hierarchy
        DataStoreException exception = new DataStoreException("Test");

        assertTrue(exception instanceof DataStoreException);

        assertNotNull(exception);
        assertEquals(message, exception.getMessage());
        assertNull(exception.getCause());
    }

    public void test_inheritance() {
        // Test that ThemeException properly extends FessSystemException
        ThemeException exception = new ThemeException("Test");

        assertTrue(exception instanceof FessSystemException);

            fail("Should be able to access private constructor: " + e.getMessage());
        }
    }

    public void test_inheritance() {
        // Verify that SystemUtil extends org.codelibs.core.lang.SystemUtil
        Class<?> superClass = SystemUtil.class.getSuperclass();

            fail("Should throw exception for null property");
        } catch (IllegalArgumentException e) {
            // Expected
        }
    }

    // Test inheritance
    public void test_inheritance() {
        assertTrue(messages instanceof FessLabels);
        assertTrue(messages instanceof org.lastaflute.core.message.UserMessages);
    }

    // Test method chaining