anchor.diff:                class="traffic-light-diff-tip-traffic-light-image"
                 src="/traffic-light/image/${colour}.png">`) +
            td(`<div class='traffic-light-diff-tip-tag ${colour}'>
  -              ${count} +
  +              ${count}
                </div>`));
     };
   
  
positive.code:       id:'hit-count',
        class:'traffic-light-count'
      }).text(counts.hit);
      const hoverTip = 'correct predictions';
      cd.setTip($hitCount, () => cd.showHoverTip($hitCount, hoverTip));
      return $('<div>', {id:'hit-box'}).append($hitImg).append($hitCount);
    };
  
negative.code:   };
  
    const prediction = (light) => {
      return light.predicted != undefined &&
               light.predicted != 'none';
    };
  
    const isRag = (s) => ['red','amber','green'].includes(s);
  