@Test
public void testGetFilledElements() throws Exception {

    final VoiceXmlDocument document = new VoiceXmlDocument();
    final Vxml vxml = document.getVxml();
    final Form form = vxml.appendChild(Form.class);
    final Filled filled = form.appendChild(Filled.class);
    form.appendChild(Noinput.class);
    form.appendChild(Help.class);
    final Catch catchNode = form.appendChild(Catch.class);
    catchNode.setEvent("test");
    final ExecutablePlainForm dialog = new ExecutablePlainForm();
    dialog.setNode(form);
    final Collection<Filled> elements = dialog.getFilledElements();
    Assert.assertEquals(1, elements.size());
    final Filled element = elements.iterator().next();
    Assert.assertTrue("expected to find filled element",
            element.isEqualNode(filled));
}