@Test
  public void appendMustCorrectlyMoveChildrenInsideOneParentElement() {
    Document doc = new Document("");
    Element body = doc.appendElement("body");
    body.appendElement("div1");
    body.appendElement("div2");
    final Element div3 = body.appendElement("div3");
    div3.text("Check");
    final Element div4 = body.appendElement("div4");

    ArrayList<Element> toMove = new ArrayList<Element>();
    toMove.add(div3);
    toMove.add(div4);

    body.insertChildren(0, toMove);

    String result = doc.toString().replaceAll("\\s+", "");
    assertEquals("<body><div3>Check</div3><div4></div4><div1></div1><div2></div2></body>", result);
  }
 @Test
 public void toStringNotNull() {
   Document model = new Document();
   assertNotNull(model.toString());
 }