final ChatMessage message = new ChatMessage();
        message.setHtmlContent("");

        assertEquals("", message.getHtmlContent());
    }

    @Test
    public void test_htmlContent_withSpecialCharacters() {
        final ChatMessage message = new ChatMessage();
        final String htmlContent = "<p>Special chars: &amp; &lt; &gt; &quot;</p>";

        message.setHtmlContent(htmlContent);