anchor.diff:    const avatarIndex = () => '<%= @manifest['group_index'] %>';
   
     const $lights = $('#traffic-lights');
  -
  -  // - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  -  // Every event has a unique index property, but there
  -  // are events that do not correspond to a visible event.
  -  // For example, the kata creation event.
  -  // In the future there may be more, eg file new|delete|rename events.
  -  // Number is the number of what will be the next visible event.
  -  // - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  -  var number = 1;
   
     // - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     // cd.appendTrafficLight() sets up the tip/click handlers
  
positive.code:       const $div = $('<div>', {
          'class':'diff-traffic-light',
          'data-id':kataId,
          'data-number':number,
          'data-index':index,
          'data-colour':light.colour
        });
  
negative.code:       $lights.append($light);
        $light.click(() => cd.review.fromTestPage(kataId, index));
        cd.setupTrafficLightTip($light, light.colour, avatarIndex, kataId, index-1, index);
        updateCountData(light);
        counts.lastLight = light;
      }
  