    Folder with some children
                        <ul>
                          <li id='tree3id2.1'>
                            Sub-item 3.1
                            <ul>
                              <li id='tree3id3.1.1'>
                                Sub-item 3.1.1
                              </li>
                              <li id='tree3id3.1.2'>
                                Sub-item 3.1.2
                              </li>
                            </ul>
                          