anchor.diff:          <td class="selectable-row">
             <div class="relative">
               <label>
  -              <input type="checkbox" checked="checked"/>
  +              <input type="checkbox" checked="checked" class="js-toggle-row" />
               </label>
             </div>
           </td>
  
positive.code:           <th class="selectable-row">
              <div class="relative">
                <label>
                  <input type="checkbox" />
                </label>
              </div>
            </th>
  
negative.code:     </tbody>
      </table>
  
      <script>GOVUK.SelectableTable.setup();</script>
    </ul>
  </div>
  <hr>
  