anchor.diff:          const barOrGap = (param.nowIndex === nowIndex) ? 'bar' : 'gap';
           html += makeTd(makeTrafficLightHtml(colour, wasIndex, nowIndex, barOrGap));
           wasIndex = nowIndex;
  -        lastColour = event.colour;
  -        trafficLightCount++;
         }
       });
  -
  -    html += makeTd(makeTrafficLightCountHtml(trafficLightCount, lastColour));
       html += makeTd(makeAvatarImageHtml());
       html += '</tr></table>';
  -
       return html;
     };
   
  
positive.code:   const makeTrafficLightsHtml = () => {
      let html = '';
      let wasIndex = 0;
      let lastColour = '';
      let trafficLightCount = 0;
      html += '<table><tr>';
      $.each(param.events, (_n, event) => {
        const colour = event.colour;
  
negative.code:     $.getJSON('/differ/diff', reviewParams, (data) => {
        $('.ui-dialog').removeClass('busy');
        param = data;
        refreshEventControls();
        refreshTrafficLights();
        refreshFiles();
        refreshForkButton();
        refreshRevertButton();
  