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