需要帮助从nestedSortable jQuery获取输出

<script src="https://code.jquery.com/jquery-3.6.0.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery-ui/1.12.1/jquery-ui.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery-ui-nestedSortable/2.0.0/jquery.ui.nestedSortable.min.js"></script>

<div id="sortable">
  <ol>
    <li id="item1">
      Item 1
      <ol>
        <li id="item1-1">Item 1.1</li>
        <li id="item1-2">Item 1.2</li>
      </ol>
    </li>
    <li id="item2">
      Item 2
      <ol>
        <li id="item2-1">Item 2.1</li>
        <li id="item2-2">Item 2.2</li>
      </ol>
    </li>
  </ol>
</div>

$(document).ready(function() {
  $('#sortable').nestedSortable({
    handle: 'div',
    items: 'li',
    toleranceElement: '> div',
    maxLevels: 3,
    placeholder: 'placeholder',
    revert: 250,
    opacity: 0.6,
    cursor: 'move',
    update: function(event, ui) {
      // 获取排序后的输出
      var output = $('#sortable').nestedSortable('toHierarchy', {startDepthCount: 0});
      console.log(output);
    }
  });
});