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