ng the option <code>subgroupOrder</code> of a group.
      </td>
    </tr>
    <tr>
      <td>title</td>
      <td>String</td>
      <td>none</td>
      <td>Add a title for the item, displayed when holding the mouse on the item.
        The title can be an HTML element or a string containing plain text or HTML.
      </td>
    </tr>
    <tr>
      <td>type</td>
      <td>String</td>
      <td>no</td>
      <td>The type of the item. Can be 'box' (default), 'point', 'range', or 'background'.
        Types 'bo