// null content with sources => returns suffix only
        assertNotNull(result);
        assertTrue(result.contains("[Referenced documents: Doc A, Doc B]"));
    }

    @Test
    public void test_sourceTitles_emptyTitles() {
        final ChatMessage msg = ChatMessage.assistantMessage("Some content here that is quite long enough to be truncated.");
        final Map<String, Object> doc = new HashMap<>();
        doc.put("title", "");