assertTrue(withNPE.getCause() instanceof NullPointerException);
        assertTrue(withCustom.getCause() instanceof FessSystemException);
    }

    public void test_getLongMessage() {
        // Test with very long message
        StringBuilder longMessage = new StringBuilder();
        for (int i = 0; i < 1000; i++) {
            longMessage.append("Error ").append(i).append(" ");
        }