anchor.diff:    HeatMap = {};
     HeatMap.dirty = false;
     HeatMap.instances = [];
  +  HeatMap.drawOrder = [];
   
     MAP_STYLES = [{"featureType":"landscape","stylers":[{"saturation":-100},{"lightness":65},{"visibility":"on"}]},{"featureType":"poi","stylers":[{"saturation":-100},{"lightness":51},{"visibility":"simplified"}]},{"featureType":"road.highway","stylers":[{"saturation":-100},{"visibility":"simplified"}]},{"featureType":"road.arterial","stylers":[{"saturation":-100},{"lightness":30},{"visibility":"on"}]},{"featureType":"road.local","stylers":[{"saturation":-100},{"lightness":40},{"visibility":"on"}]},{"featureType":"transit","stylers":[{"saturation":-100},{"visibility":"simplified"}]},{"featureType":"administrative.province","stylers":[{"visibility":"off"}]},{"featureType":"water","elementType":"labels","stylers":[{"visibility":"on"},{"lightness":-25},{"saturation":-100}]},{"featureType":"water","elementType":"geometry","stylers":[{"hue":"#ffff00"},{"lightness":-25},{"saturation":-97}]}];
   
  
positive.code:   }
  
    function display_heatmaps() {
      opacity = 1.0 / HeatMap.state.filters.length;
      _.each(HeatMap.points, function(points, index){
        if (_.isUndefined(HeatMap.instances[index])) {
          HeatMap.instances[index] = new google.maps.visualization.HeatmapLayer({
            map: null,
            radius: 0.03,
            dissipating: false,
            opacity: opacity,
            maxIntensity: 1.0
          });
        }
  
negative.code:         }
        });
        HeatMap.instances[index].setData(points);
        if (HeatMap.state.filters[index].visible) {
          if (_.isNull(HeatMap.instances[index].map)) {
            HeatMap.instances[index].setMap(map);
            HeatMap.drawOrder.push(index);
          }
        } else {
          if (!_.isNull(HeatMap.instances[index].map)) {
            HeatMap.instances[index].setMap(null);
            HeatMap.drawOrder = _.without(HeatMap.drawOrder, index);
          }
        }
      });
      attenuation = 1.0;
      if (map.zoom > 12) {
        attenuation = (21 - map.zoom) / 9.0;
      }
      opacity = 0.9;
      opacity *= attenuation;
      _.each(HeatMap.drawOrder, function(order, index){
        HeatMap.instances[order].set('opacity', opacity);
        opacity *= 0.7;
      });
    }
  
  