public static void addMoodToMessage(Message message, Mood mood) {
        addMoodToMessage(message, mood, null);
    }
@Test
    public void addMessageTest() {
        Message message = StanzaBuilder.buildMessage().build();
        MoodManager.addMoodToMessage(message, Mood.sad);

        assertTrue(message.hasExtension(MoodElement.ELEMENT, MoodElement.NAMESPACE));
        assertTrue(MoodElement.hasMoodElement(message));
        MoodElement element = MoodElement.fromMessage(message);
        assertNotNull(element);
        assertEquals(Mood.sad, element.getMood());
        assertFalse(element.hasConcretisation());
        assertFalse(element.hasText());

        message = StanzaBuilder.buildMessage().build();
        MoodManager.addMoodToMessage(message, Mood.happy, new MoodConcretisationTest.EcstaticMoodConcretisation());
        element = MoodElement.fromMessage(message);
        assertTrue(element.hasConcretisation());
    }