assertEquals("# Title\n\nParagraph", message.getContent());
        assertEquals("<h1>Title</h1><p>Paragraph</p>", message.getHtmlContent());
    }

    @Test
    public void test_htmlContent_setNull() {
        final ChatMessage message = new ChatMessage();
        message.setHtmlContent("<p>content</p>");
        message.setHtmlContent(null);

        assertNull(message.getHtmlContent());
    }