anchor.diff:  
     // - - - - - - - - - - - - - - - - - - - - - - - -
   
  -  const visible = (event) => {
  +  const isVisible = (event) => {
       // eg don't show event[0] == creation
       switch (event.colour) {
       case 'pulling':
  
positive.code:     let html = '';
      let number = 1;
      $.each(param.events, (_index, event) => {
        if (visible(event)) {
          html += makeTrafficLightHtml(event, number);
          number += 1;
        }
  
negative.code:   };
  
    //-----------------------------------------
    // traffic-lights...
    //-----------------------------------------
  
    const refreshTrafficLights = () => {
  