code: function intersects(e) {
      if( !this.showing ) return;
  
      var dpp = this.getDegreesPerPx(e.latlng);
  
      var mpp = this.getMetersPerPx(e.latlng);
      var r = mpp * 5; // 5 px radius buffer;
  
      var center = {
        type : 'Point',
        coordinates : [e.latlng.lng, e.latlng.lat]
      };
  
      var containerPoint = e.containerPoint;
  
      var x1 = e.latlng.lng - dpp;
      var x2 = e.latlng.lng + dpp;
      var y1 = e.latlng.lat - dpp;
      var y2 = e.latlng.lat + dpp;
  
      var intersects = this.intersectsBbox([[x1, y1], [x2, y2]], r, center, containerPoint);
  
      onIntersectsListCreated.call(this, e, intersects);
  }
docs: Handle mouse intersection events
  e - leaflet event