assertEquals("system", LlmMessage.ROLE_SYSTEM);
        assertEquals("user", LlmMessage.ROLE_USER);
        assertEquals("assistant", LlmMessage.ROLE_ASSISTANT);
    }

    @Test
    public void test_toStringShortContent() {
        final LlmMessage message = new LlmMessage("user", "Short content");
        final String str = message.toString();
        assertTrue(str.contains("role='user'"));