an be clicked</li>
          <li>Click one and then try to click another</li>
        </ul>
      </div>
      <script>
      /* Wrap handler in once function for once ever firing */
      addListener('#click-list-once-ever li', 'click', once((e) => {
        console.log(`Clicked`, e.target)
        console.log('This handler only fires once')
        window.liOnceCount = window.liOnceCount + 1 // for tests
        incrementCount(e)
      }));
      </script>


      <div>
        <h3>Comma separated events 