How to add cluster support to the directive? about angular-leaflet-directive HOT 10 CLOSED

if (attrs.clustermarkers !== undefined) {
                scope.showuser=function(id){
                    console.log(id);
                }
                var cluster_markers_dict = [];
                var cluster = new L.MarkerClusterGroup();

                var createAndLinkCluster = function(mkey, scope) {
                    var markerData = scope.clustermarkers[mkey];
                    var marker = new L.marker(
                        [markerData.lat, markerData.lng],
                        {
                        }
                    );

                    if (markerData.message) {
                        scope.$watch("clustermarkers." + mkey + ".message", function(newValue) { 
                            marker.bindPopup(markerData.message);
                        });

                        scope.$watch("clustermarkers." + mkey + ".focus", function(newValue) {
                            if (newValue) {
                                marker.openPopup();
                            }
                        });
                    }

                    return marker;
                }; // end of create and link marker

                scope.$watch("clustermarkers", function(newMarkerList) {
                    // find deleted markers

                    for (var delkey in cluster_markers_dict) {
                        if (!scope.clustermarkers[delkey]) {
                            cluster.removeLayer(cluster_markers_dict[delkey]);
                            delete cluster_markers_dict[delkey];
                        }
                    }
                    // add new markers
                    for (var mkey in scope.clustermarkers) {
                        if (cluster_markers_dict[mkey] === undefined) {
                            var marker = createAndLinkCluster(mkey, scope);
                            cluster_markers_dict[mkey] = marker;
                            cluster.addLayer(marker);
                        }
                    } // for mkey in markers
                    if(cluster_markers_dict.length>4)
                    {
                        map.addLayer(cluster);
                    }

                }, true); // watch markers
            } // if attrs.markers