anchor.diff:        const $div = $('<div>', {
           'class':'diff-traffic-light',
           'data-id':kataId,
  -        'data-number':number,
           'data-index':index,
           'data-colour':light.colour
         });
  
positive.code:       $lights.append($light);
        $light.click(() => cd.review.fromTestPage(kataId, index));
        cd.setupTrafficLightTip($light, light.colour, avatarIndex, kataId, index-1, index);
        number += 1;
        updateCountData(light);
        counts.lastLight = light;
      }
  
negative.code:   const avatarIndex = () => '<%= @manifest['group_index'] %>';
  
    const $lights = $('#traffic-lights');
  
    // - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    // cd.appendTrafficLight() sets up the tip/click handlers
  