assertSame(request, result);
        assertEquals(1, request.getMessages().size());
        assertEquals("Test message", request.getMessages().get(0).getContent());
    }

    @Test
    public void test_addSystemMessage() {
        final LlmChatRequest request = new LlmChatRequest();

        final LlmChatRequest result = request.addSystemMessage("System prompt");

        assertSame(request, result);