           <input type="checkbox" id="enable_vc" checked>
            </label>
            <br>
            <label>
              Show Porthos:
              <input type="checkbox" id="show_porthos" checked>
            </label>
            &nbsp;
            <label>
              Enable Porthos:
              <input type="checkbox" id="enable_porthos">
            </label>
            <br>
            <label>
              Enable transition events:
              <input type="checkbox" id="enable_vc_events"