anchor.diff:    // - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     // cd.updateTrafficLightsCount() updates the total and predicted counts.
     // It is called from two places:
  -  //   1) kata/edit when page loads/refreshes.
  +  //   1) _edit.html.erb when page loads/refreshes.
     //   2) run_tests.js.erb when [test] is clicked.
   
     cd.updateTrafficLightsCount = () => {
  
positive.code:   const totalCount = () => {
      const total = counts.red + counts.amber + counts.green + counts.timed_out;
      return $('<div>', {
        'class': `traffic-light-count ${lastColour()}`,
      }).text(total);
    };
  
    const lastColour = () => {
      const last = counts.lastLight;
      return last ? last.colour : '';
    };
  
    const trafficLightsTotalCountHoverTip = () => {
      let html = '';
      html += '<table>';
      html += trLight('red', counts.red);
      html += trLight('amber', counts.amber);
      html += trLight('green', counts.green);
      if (counts.timed_out > 0) {
        html += trLight('timed_out', counts.timed_out);
      }
      html += '</table>';
      return html;
    };
  
    const trLight = (colour, count) => {
      const tr = (s) => `<tr>${s}</tr>`;
      const td = (s) => `<td>${s}</td>`;
      return '' +
  
negative.code:     wasIndex(index);
    };
  
    const updateCountData = (light) => {
      counts[light.colour] += 1;
      if (prediction(light)) {
        if (light.colour === light.predicted) {
          counts.hit += 1;
        } else {
          counts.miss += 1;
  