问如何解决这个MarkerCluster签出/签出错误(传单销售)？

EN

I saw that this function from DistanceGrid(is in leaflet library) which is called when i check in on the overlay 

_sqDist: function (p, p2) {
      var dx = p2.x - p.x,
          dy = p2.y - p.y;
      return dx * dx + dy * dy;
  }

JS controller: 
var map = L.map('map', {zoomControl: true, tap: false, preferCanvas:true})
var group1,group2,group3,group4;
var myRenderer = L.canvas({ padding: 0.5 });
 var markers = L.markerClusterGroup.layerSupport( { 
        chunkedLoading: true,
        renderer: myRenderer,
        iconCreateFunction: function  (cluster) {
        var childCount = cluster.getChildCount();

        var c = ' marker-cluster-';
        if (childCount < 10) {
            c += 'small';
        } 
        else if (childCount < 100) {
            c += 'medium';
        } 
        else {
                c += 'large';
        }

        return new L.DivIcon({ html: '<div><span>' + childCount + '</span> 
</div>', 
                              className: 'marker-cluster' + c, iconSize: 
 new L.Point(40, 40) });
            }
});

 group1 = L.layerGroup(),
       group2 = L.layerGroup(),
      group3 = L.layerGroup(),
       group4 = L.layerGroup(),

    markers.checkIn([group1, group2, group3, group4]);

    var overlayMaps = {
        "g1": group1,
        "g2": group2,
        "g3":group3,
        "g4":group4
    };
    var control = L.control.layers(null, overlayMaps, { collapsed: true });


    control.addTo(map);

    group1.addTo(map); // Adding to map or to AutoMCG are now equivalent.
    group2.addTo(map);
    group3.addTo(map);
    group4.addTo(map);

 markers.addTo(map);