优化逻辑

YANGDL

2021-01-05 1820aef3fb5c926664de1d4d484f64a5c9ba7099

 src/components/plugin/cluster-layer/leaflet.markercluster-src.js

@@ -1,1095 +1,1086 @@
'use strict';
function init(L) {
    /*
'use strict'
function init (L) {
  /*
     * L.MarkerClusterGroup extends L.FeatureGroup by clustering the markers contained within
     */

    var MarkerClusterGroup = L.MarkerClusterGroup = L.FeatureGroup.extend({
  var MarkerClusterGroup = L.MarkerClusterGroup = L.FeatureGroup.extend({

        options: {
            maxClusterRadius: 80, // A cluster will cover at most this many pixels from its center
            iconCreateFunction: null,
            clusterPane: L.Marker.prototype.options.pane,
    options: {
      maxClusterRadius: 80, // A cluster will cover at most this many pixels from its center
      iconCreateFunction: null,
      clusterPane: L.Marker.prototype.options.pane,

            spiderfyOnMaxZoom: true,
            showCoverageOnHover: true,
            zoomToBoundsOnClick: true,
            singleMarkerMode: false,
      spiderfyOnMaxZoom: true,
      showCoverageOnHover: true,
      zoomToBoundsOnClick: true,
      singleMarkerMode: false,

            disableClusteringAtZoom: null,
      disableClusteringAtZoom: null,

            //  Setting this to false prevents the removal of any clusters outside of the viewpoint, which
            //  is the default behaviour for performance reasons.
            removeOutsideVisibleBounds: true,
      //  Setting this to false prevents the removal of any clusters outside of the viewpoint, which
      //  is the default behaviour for performance reasons.
      removeOutsideVisibleBounds: true,

            //  Set to false to disable all animations (zoom and spiderfy).
            //  If false, option animateAddingMarkers below has no effect.
            //  If L.DomUtil.TRANSITION is falsy, this option has no effect.
            animate: true,
      //  Set to false to disable all animations (zoom and spiderfy).
      //  If false, option animateAddingMarkers below has no effect.
      //  If L.DomUtil.TRANSITION is falsy, this option has no effect.
      animate: true,

            // Whether to animate adding markers after adding the MarkerClusterGroup to the map
            //  If you are adding individual markers set to true, if adding bulk markers leave false for massive performance gains.
            animateAddingMarkers: false,
      // Whether to animate adding markers after adding the MarkerClusterGroup to the map
      //  If you are adding individual markers set to true, if adding bulk markers leave false for massive performance gains.
      animateAddingMarkers: false,

            // Increase to increase the distance away that spiderfied markers appear from the center
            spiderfyDistanceMultiplier: 1,
      // Increase to increase the distance away that spiderfied markers appear from the center
      spiderfyDistanceMultiplier: 1,

            //  Make it possible to specify a polyline options on a spider leg
            spiderLegPolylineOptions: {weight: 1.5, color: '#222', opacity: 0.5},
      //  Make it possible to specify a polyline options on a spider leg
      spiderLegPolylineOptions: { weight: 1.5, color: '#222', opacity: 0.5 },

            //  When bulk adding layers, adds markers in chunks. Means addLayers may not add all the layers in the call, others will be loaded during setTimeouts
            chunkedLoading: false,
            chunkInterval: 200, //  process markers for a maximum of ~ n milliseconds (then trigger the chunkProgress callback)
            chunkDelay: 50, //  at the end of each interval, give n milliseconds back to system/browser
            chunkProgress: null, //  progress callback: function(processed, total, elapsed) (e.g. for a progress indicator)
      //  When bulk adding layers, adds markers in chunks. Means addLayers may not add all the layers in the call, others will be loaded during setTimeouts
      chunkedLoading: false,
      chunkInterval: 200, //  process markers for a maximum of ~ n milliseconds (then trigger the chunkProgress callback)
      chunkDelay: 50, //  at the end of each interval, give n milliseconds back to system/browser
      chunkProgress: null, //  progress callback: function(processed, total, elapsed) (e.g. for a progress indicator)

            // Options to pass to the L.Polygon constructor
            polygonOptions: {}
        },
      // Options to pass to the L.Polygon constructor
      polygonOptions: {}
    },

        initialize: function(options) {
            L.Util.setOptions(this, options);
            if (!this.options.iconCreateFunction) {
                this.options.iconCreateFunction = this._defaultIconCreateFunction;
    initialize: function (options) {
      L.Util.setOptions(this, options)
      if (!this.options.iconCreateFunction) {
        this.options.iconCreateFunction = this._defaultIconCreateFunction
      }

      this._featureGroup = L.featureGroup()
      this._featureGroup.addEventParent(this)

      this._nonPointGroup = L.featureGroup()
      this._nonPointGroup.addEventParent(this)

      this._inZoomAnimation = 0
      this._needsClustering = []
      this._needsRemoving = [] // Markers removed while we aren't on the map need to be kept track of
      // The bounds of the currently shown area (from _getExpandedVisibleBounds) Updated on zoom/move
      this._currentShownBounds = null

      this._queue = []

      this._childMarkerEventHandlers = {
        dragstart: this._childMarkerDragStart,
        move: this._childMarkerMoved,
        dragend: this._childMarkerDragEnd
      }

      //  Hook the appropriate animation methods.
      var animate = L.DomUtil.TRANSITION && this.options.animate
      L.extend(this, animate ? this._withAnimation : this._noAnimation)
      //  Remember which MarkerCluster class to instantiate (animated or not).
      this._markerCluster = animate ? L.MarkerCluster : L.MarkerClusterNonAnimated
    },

    addLayer: function (layer) {
      if (layer instanceof L.LayerGroup) {
        return this.addLayers([layer])
      }

      // Don't cluster non point data
      if (!layer.getLatLng) {
        this._nonPointGroup.addLayer(layer)
        this.fire('layeradd', { layer: layer })
        return this
      }

      if (!this._map) {
        this._needsClustering.push(layer)
        this.fire('layeradd', { layer: layer })
        return this
      }

      if (this.hasLayer(layer)) {
        return this
      }

      // If we have already clustered we'll need to add this one to a cluster

      if (this._unspiderfy) {
        this._unspiderfy()
      }

      this._addLayer(layer, this._maxZoom)
      this.fire('layeradd', { layer: layer })

      //  Refresh bounds and weighted positions.
      this._topClusterLevel._recalculateBounds()

      this._refreshClustersIcons()

      // Work out what is visible
      var visibleLayer = layer
      var currentZoom = this._zoom
      if (layer.__parent) {
        while (visibleLayer.__parent._zoom >= currentZoom) {
          visibleLayer = visibleLayer.__parent
        }
      }

      if (this._currentShownBounds.contains(visibleLayer.getLatLng())) {
        if (this.options.animateAddingMarkers) {
          this._animationAddLayer(layer, visibleLayer)
        } else {
          this._animationAddLayerNonAnimated(layer, visibleLayer)
        }
      }
      return this
    },

    removeLayer: function (layer) {
      if (layer instanceof L.LayerGroup) {
        return this.removeLayers([layer])
      }

      // Non point layers
      if (!layer.getLatLng) {
        this._nonPointGroup.removeLayer(layer)
        this.fire('layerremove', { layer: layer })
        return this
      }

      if (!this._map) {
        if (!this._arraySplice(this._needsClustering, layer) && this.hasLayer(layer)) {
          this._needsRemoving.push({ layer: layer, latlng: layer._latlng })
        }
        this.fire('layerremove', { layer: layer })
        return this
      }

      if (!layer.__parent) {
        return this
      }

      if (this._unspiderfy) {
        this._unspiderfy()
        this._unspiderfyLayer(layer)
      }

      // Remove the marker from clusters
      this._removeLayer(layer, true)
      this.fire('layerremove', { layer: layer })

      //  Refresh bounds and weighted positions.
      this._topClusterLevel._recalculateBounds()

      this._refreshClustersIcons()

      layer.off(this._childMarkerEventHandlers, this)

      if (this._featureGroup.hasLayer(layer)) {
        this._featureGroup.removeLayer(layer)
        if (layer.clusterShow) {
          layer.clusterShow()
        }
      }

      return this
    },

    // Takes an array of markers and adds them in bulk
    addLayers: function (layersArray, skipLayerAddEvent) {
      if (!L.Util.isArray(layersArray)) {
        return this.addLayer(layersArray)
      }

      var fg = this._featureGroup
      var npg = this._nonPointGroup
      var chunked = this.options.chunkedLoading
      var chunkInterval = this.options.chunkInterval
      var chunkProgress = this.options.chunkProgress
      var l = layersArray.length
      var offset = 0
      var originalArray = true
      var m

      if (this._map) {
        var started = (new Date()).getTime()
        var process = L.bind(function () {
          var start = (new Date()).getTime()
          for (; offset < l; offset++) {
            if (chunked && offset % 200 === 0) {
              //  every couple hundred markers, instrument the time elapsed since processing started:
              var elapsed = (new Date()).getTime() - start
              if (elapsed > chunkInterval) {
                break //  been working too hard, time to take a break :-)
              }
            }

            this._featureGroup = L.featureGroup();
            this._featureGroup.addEventParent(this);
            m = layersArray[offset]

            this._nonPointGroup = L.featureGroup();
            this._nonPointGroup.addEventParent(this);

            this._inZoomAnimation = 0;
            this._needsClustering = [];
            this._needsRemoving = []; // Markers removed while we aren't on the map need to be kept track of
            // The bounds of the currently shown area (from _getExpandedVisibleBounds) Updated on zoom/move
            this._currentShownBounds = null;

            this._queue = [];

            this._childMarkerEventHandlers = {
                'dragstart': this._childMarkerDragStart,
                'move': this._childMarkerMoved,
                'dragend': this._childMarkerDragEnd,
            };

            //  Hook the appropriate animation methods.
            var animate = L.DomUtil.TRANSITION && this.options.animate;
            L.extend(this, animate ? this._withAnimation : this._noAnimation);
            //  Remember which MarkerCluster class to instantiate (animated or not).
            this._markerCluster = animate ? L.MarkerCluster : L.MarkerClusterNonAnimated;
        },

        addLayer: function(layer) {

            if (layer instanceof L.LayerGroup) {
                return this.addLayers([layer]);
            //  Group of layers, append children to layersArray and skip.
            //  Side effects:
            //  - Total increases, so chunkProgress ratio jumps backward.
            //  - Groups are not included in this group, only their non-group child layers (hasLayer).
            //  Changing array length while looping does not affect performance in current browsers:
            //  http:// jsperf.com/for-loop-changing-length/6
            if (m instanceof L.LayerGroup) {
              if (originalArray) {
                layersArray = layersArray.slice()
                originalArray = false
              }
              this._extractNonGroupLayers(m, layersArray)
              l = layersArray.length
              continue
            }

            // Don't cluster non point data
            if (!layer.getLatLng) {
                this._nonPointGroup.addLayer(layer);
                this.fire('layeradd', {layer: layer});
                return this;
            // Not point data, can't be clustered
            if (!m.getLatLng) {
              npg.addLayer(m)
              if (!skipLayerAddEvent) {
                this.fire('layeradd', { layer: m })
              }
              continue
            }

            if (!this._map) {
                this._needsClustering.push(layer);
                this.fire('layeradd', {layer: layer});
                return this;
            if (this.hasLayer(m)) {
              continue
            }

            if (this.hasLayer(layer)) {
                return this;
            this._addLayer(m, this._maxZoom)
            if (!skipLayerAddEvent) {
              this.fire('layeradd', { layer: m })
            }


            // If we have already clustered we'll need to add this one to a cluster

            if (this._unspiderfy) {
                this._unspiderfy();
            // If we just made a cluster of size 2 then we need to remove the other marker from the map (if it is) or we never will
            if (m.__parent) {
              if (m.__parent.getChildCount() === 2) {
                var markers = m.__parent.getAllChildMarkers()
                var otherMarker = markers[0] === m ? markers[1] : markers[0]
                fg.removeLayer(otherMarker)
              }
            }
          }

            this._addLayer(layer, this._maxZoom);
            this.fire('layeradd', {layer: layer});
          if (chunkProgress) {
            //  report progress and time elapsed:
            chunkProgress(offset, l, (new Date()).getTime() - started)
          }

          //  Completed processing all markers.
          if (offset === l) {
            //  Refresh bounds and weighted positions.
            this._topClusterLevel._recalculateBounds();
            this._topClusterLevel._recalculateBounds()

            this._refreshClustersIcons();
            this._refreshClustersIcons()

            // Work out what is visible
            var visibleLayer = layer,
                currentZoom = this._zoom;
            if (layer.__parent) {
                while (visibleLayer.__parent._zoom >= currentZoom) {
                    visibleLayer = visibleLayer.__parent;
                }
            this._topClusterLevel._recursivelyAddChildrenToMap(null, this._zoom, this._currentShownBounds)
          } else {
            setTimeout(process, this.options.chunkDelay)
          }
        }, this)

        process()
      } else {
        var needsClustering = this._needsClustering

        for (; offset < l; offset++) {
          m = layersArray[offset]

          //  Group of layers, append children to layersArray and skip.
          if (m instanceof L.LayerGroup) {
            if (originalArray) {
              layersArray = layersArray.slice()
              originalArray = false
            }
            this._extractNonGroupLayers(m, layersArray)
            l = layersArray.length
            continue
          }

            if (this._currentShownBounds.contains(visibleLayer.getLatLng())) {
                if (this.options.animateAddingMarkers) {
                    this._animationAddLayer(layer, visibleLayer);
                } else {
                    this._animationAddLayerNonAnimated(layer, visibleLayer);
                }
          // Not point data, can't be clustered
          if (!m.getLatLng) {
            npg.addLayer(m)
            continue
          }

          if (this.hasLayer(m)) {
            continue
          }

          needsClustering.push(m)
        }
      }
      return this
    },

    // Takes an array of markers and removes them in bulk
    removeLayers: function (layersArray) {
      var i; var m
      var l = layersArray.length
      var fg = this._featureGroup
      var npg = this._nonPointGroup
      var originalArray = true

      if (!this._map) {
        for (i = 0; i < l; i++) {
          m = layersArray[i]

          //  Group of layers, append children to layersArray and skip.
          if (m instanceof L.LayerGroup) {
            if (originalArray) {
              layersArray = layersArray.slice()
              originalArray = false
            }
            return this;
        },
            this._extractNonGroupLayers(m, layersArray)
            l = layersArray.length
            continue
          }

        removeLayer: function(layer) {
          this._arraySplice(this._needsClustering, m)
          npg.removeLayer(m)
          if (this.hasLayer(m)) {
            this._needsRemoving.push({ layer: m, latlng: m._latlng })
          }
          this.fire('layerremove', { layer: m })
        }
        return this
      }

            if (layer instanceof L.LayerGroup) {
                return this.removeLayers([layer]);
            }
      if (this._unspiderfy) {
        this._unspiderfy()

            // Non point layers
            if (!layer.getLatLng) {
                this._nonPointGroup.removeLayer(layer);
                this.fire('layerremove', {layer: layer});
                return this;
            }
        //  Work on a copy of the array, so that next loop is not affected.
        var layersArray2 = layersArray.slice()
        var l2 = l
        for (i = 0; i < l2; i++) {
          m = layersArray2[i]

            if (!this._map) {
                if (!this._arraySplice(this._needsClustering, layer) && this.hasLayer(layer)) {
                    this._needsRemoving.push({layer: layer, latlng: layer._latlng});
                }
                this.fire('layerremove', {layer: layer});
                return this;
            }
          //  Group of layers, append children to layersArray and skip.
          if (m instanceof L.LayerGroup) {
            this._extractNonGroupLayers(m, layersArray2)
            l2 = layersArray2.length
            continue
          }

            if (!layer.__parent) {
                return this;
            }
          this._unspiderfyLayer(m)
        }
      }

            if (this._unspiderfy) {
                this._unspiderfy();
                this._unspiderfyLayer(layer);
            }
      for (i = 0; i < l; i++) {
        m = layersArray[i]

            // Remove the marker from clusters
            this._removeLayer(layer, true);
            this.fire('layerremove', {layer: layer});
        //  Group of layers, append children to layersArray and skip.
        if (m instanceof L.LayerGroup) {
          if (originalArray) {
            layersArray = layersArray.slice()
            originalArray = false
          }
          this._extractNonGroupLayers(m, layersArray)
          l = layersArray.length
          continue
        }

            //  Refresh bounds and weighted positions.
            this._topClusterLevel._recalculateBounds();
        if (!m.__parent) {
          npg.removeLayer(m)
          this.fire('layerremove', { layer: m })
          continue
        }

            this._refreshClustersIcons();
        this._removeLayer(m, true, true)
        this.fire('layerremove', { layer: m })

            layer.off(this._childMarkerEventHandlers, this);
        if (fg.hasLayer(m)) {
          fg.removeLayer(m)
          if (m.clusterShow) {
            m.clusterShow()
          }
        }
      }

            if (this._featureGroup.hasLayer(layer)) {
                this._featureGroup.removeLayer(layer);
                if (layer.clusterShow) {
                    layer.clusterShow();
                }
            }
      //  Refresh bounds and weighted positions.
      this._topClusterLevel._recalculateBounds()

            return this;
        },
      this._refreshClustersIcons()

        // Takes an array of markers and adds them in bulk
        addLayers: function(layersArray, skipLayerAddEvent) {
            if (!L.Util.isArray(layersArray)) {
                return this.addLayer(layersArray);
            }
      // Fix up the clusters and markers on the map
      this._topClusterLevel._recursivelyAddChildrenToMap(null, this._zoom, this._currentShownBounds)

            var fg = this._featureGroup,
                npg = this._nonPointGroup,
                chunked = this.options.chunkedLoading,
                chunkInterval = this.options.chunkInterval,
                chunkProgress = this.options.chunkProgress,
                l = layersArray.length,
                offset = 0,
                originalArray = true,
                m;
      return this
    },

            if (this._map) {
                var started = (new Date()).getTime();
                var process = L.bind(function() {
                    var start = (new Date()).getTime();
                    for (; offset < l; offset++) {
                        if (chunked && offset % 200 === 0) {
                            //  every couple hundred markers, instrument the time elapsed since processing started:
                            var elapsed = (new Date()).getTime() - start;
                            if (elapsed > chunkInterval) {
                                break; //  been working too hard, time to take a break :-)
                            }
                        }
    // Removes all layers from the MarkerClusterGroup
    clearLayers: function () {
      // Need our own special implementation as the LayerGroup one doesn't work for us

                        m = layersArray[offset];
      // If we aren't on the map (yet), blow away the markers we know of
      if (!this._map) {
        this._needsClustering = []
        this._needsRemoving = []
        delete this._gridClusters
        delete this._gridUnclustered
      }

                        //  Group of layers, append children to layersArray and skip.
                        //  Side effects:
                        //  - Total increases, so chunkProgress ratio jumps backward.
                        //  - Groups are not included in this group, only their non-group child layers (hasLayer).
                        //  Changing array length while looping does not affect performance in current browsers:
                        //  http:// jsperf.com/for-loop-changing-length/6
                        if (m instanceof L.LayerGroup) {
                            if (originalArray) {
                                layersArray = layersArray.slice();
                                originalArray = false;
                            }
                            this._extractNonGroupLayers(m, layersArray);
                            l = layersArray.length;
                            continue;
                        }
      if (this._noanimationUnspiderfy) {
        this._noanimationUnspiderfy()
      }

                        // Not point data, can't be clustered
                        if (!m.getLatLng) {
                            npg.addLayer(m);
                            if (!skipLayerAddEvent) {
                                this.fire('layeradd', {layer: m});
                            }
                            continue;
                        }
      // Remove all the visible layers
      this._featureGroup.clearLayers()
      this._nonPointGroup.clearLayers()

                        if (this.hasLayer(m)) {
                            continue;
                        }
      this.eachLayer(function (marker) {
        marker.off(this._childMarkerEventHandlers, this)
        delete marker.__parent
      }, this)

                        this._addLayer(m, this._maxZoom);
                        if (!skipLayerAddEvent) {
                            this.fire('layeradd', {layer: m});
                        }
      if (this._map) {
        // Reset _topClusterLevel and the DistanceGrids
        this._generateInitialClusters()
      }

                        // If we just made a cluster of size 2 then we need to remove the other marker from the map (if it is) or we never will
                        if (m.__parent) {
                            if (m.__parent.getChildCount() === 2) {
                                var markers = m.__parent.getAllChildMarkers(),
                                    otherMarker = markers[0] === m ? markers[1] : markers[0];
                                fg.removeLayer(otherMarker);
                            }
                        }
                    }
      return this
    },

                    if (chunkProgress) {
                        //  report progress and time elapsed:
                        chunkProgress(offset, l, (new Date()).getTime() - started);
                    }
    // Override FeatureGroup.getBounds as it doesn't work
    getBounds: function () {
      var bounds = new L.LatLngBounds()

                    //  Completed processing all markers.
                    if (offset === l) {
      if (this._topClusterLevel) {
        bounds.extend(this._topClusterLevel._bounds)
      }

                        //  Refresh bounds and weighted positions.
                        this._topClusterLevel._recalculateBounds();
      for (var i = this._needsClustering.length - 1; i >= 0; i--) {
        bounds.extend(this._needsClustering[i].getLatLng())
      }

                        this._refreshClustersIcons();
      bounds.extend(this._nonPointGroup.getBounds())

                        this._topClusterLevel._recursivelyAddChildrenToMap(null, this._zoom, this._currentShownBounds);
                    } else {
                        setTimeout(process, this.options.chunkDelay);
                    }
                }, this);
      return bounds
    },

                process();
            } else {
                var needsClustering = this._needsClustering;
    // Overrides LayerGroup.eachLayer
    eachLayer: function (method, context) {
      var markers = this._needsClustering.slice()
      var needsRemoving = this._needsRemoving
      var thisNeedsRemoving; var i; var j

                for (; offset < l; offset++) {
                    m = layersArray[offset];
      if (this._topClusterLevel) {
        this._topClusterLevel.getAllChildMarkers(markers)
      }

                    //  Group of layers, append children to layersArray and skip.
                    if (m instanceof L.LayerGroup) {
                        if (originalArray) {
                            layersArray = layersArray.slice();
                            originalArray = false;
                        }
                        this._extractNonGroupLayers(m, layersArray);
                        l = layersArray.length;
                        continue;
                    }
      for (i = markers.length - 1; i >= 0; i--) {
        thisNeedsRemoving = true

                    // Not point data, can't be clustered
                    if (!m.getLatLng) {
                        npg.addLayer(m);
                        continue;
                    }
        for (j = needsRemoving.length - 1; j >= 0; j--) {
          if (needsRemoving[j].layer === markers[i]) {
            thisNeedsRemoving = false
            break
          }
        }

                    if (this.hasLayer(m)) {
                        continue;
                    }
        if (thisNeedsRemoving) {
          method.call(context, markers[i])
        }
      }

                    needsClustering.push(m);
                }
            }
            return this;
        },
      this._nonPointGroup.eachLayer(method, context)
    },

        // Takes an array of markers and removes them in bulk
        removeLayers: function(layersArray) {
            var i, m,
                l = layersArray.length,
                fg = this._featureGroup,
                npg = this._nonPointGroup,
                originalArray = true;
    // Overrides LayerGroup.getLayers
    getLayers: function () {
      var layers = []
      this.eachLayer(function (l) {
        layers.push(l)
      })
      return layers
    },

            if (!this._map) {
                for (i = 0; i < l; i++) {
                    m = layersArray[i];
    // Overrides LayerGroup.getLayer, WARNING: Really bad performance
    getLayer: function (id) {
      var result = null

                    //  Group of layers, append children to layersArray and skip.
                    if (m instanceof L.LayerGroup) {
                        if (originalArray) {
                            layersArray = layersArray.slice();
                            originalArray = false;
                        }
                        this._extractNonGroupLayers(m, layersArray);
                        l = layersArray.length;
                        continue;
                    }
      id = parseInt(id, 10)

                    this._arraySplice(this._needsClustering, m);
                    npg.removeLayer(m);
                    if (this.hasLayer(m)) {
                        this._needsRemoving.push({layer: m, latlng: m._latlng});
                    }
                    this.fire('layerremove', {layer: m});
                }
                return this;
            }
      this.eachLayer(function (l) {
        if (L.stamp(l) === id) {
          result = l
        }
      })

            if (this._unspiderfy) {
                this._unspiderfy();
      return result
    },

                //  Work on a copy of the array, so that next loop is not affected.
                var layersArray2 = layersArray.slice(),
                    l2 = l;
                for (i = 0; i < l2; i++) {
                    m = layersArray2[i];
    // Returns true if the given layer is in this MarkerClusterGroup
    hasLayer: function (layer) {
      if (!layer) {
        return false
      }

                    //  Group of layers, append children to layersArray and skip.
                    if (m instanceof L.LayerGroup) {
                        this._extractNonGroupLayers(m, layersArray2);
                        l2 = layersArray2.length;
                        continue;
                    }
      var i; var anArray = this._needsClustering

                    this._unspiderfyLayer(m);
                }
            }
      for (i = anArray.length - 1; i >= 0; i--) {
        if (anArray[i] === layer) {
          return true
        }
      }

            for (i = 0; i < l; i++) {
                m = layersArray[i];
      anArray = this._needsRemoving
      for (i = anArray.length - 1; i >= 0; i--) {
        if (anArray[i].layer === layer) {
          return false
        }
      }

                //  Group of layers, append children to layersArray and skip.
                if (m instanceof L.LayerGroup) {
                    if (originalArray) {
                        layersArray = layersArray.slice();
                        originalArray = false;
                    }
                    this._extractNonGroupLayers(m, layersArray);
                    l = layersArray.length;
                    continue;
                }
      return !!(layer.__parent && layer.__parent._group === this) || this._nonPointGroup.hasLayer(layer)
    },

                if (!m.__parent) {
                    npg.removeLayer(m);
                    this.fire('layerremove', {layer: m});
                    continue;
                }

                this._removeLayer(m, true, true);
                this.fire('layerremove', {layer: m});

                if (fg.hasLayer(m)) {
                    fg.removeLayer(m);
                    if (m.clusterShow) {
                        m.clusterShow();
                    }
                }
            }

            //  Refresh bounds and weighted positions.
            this._topClusterLevel._recalculateBounds();

            this._refreshClustersIcons();

            // Fix up the clusters and markers on the map
            this._topClusterLevel._recursivelyAddChildrenToMap(null, this._zoom, this._currentShownBounds);

            return this;
        },

        // Removes all layers from the MarkerClusterGroup
        clearLayers: function() {
            // Need our own special implementation as the LayerGroup one doesn't work for us

            // If we aren't on the map (yet), blow away the markers we know of
            if (!this._map) {
                this._needsClustering = [];
                this._needsRemoving = [];
                delete this._gridClusters;
                delete this._gridUnclustered;
            }

            if (this._noanimationUnspiderfy) {
                this._noanimationUnspiderfy();
            }

            // Remove all the visible layers
            this._featureGroup.clearLayers();
            this._nonPointGroup.clearLayers();

            this.eachLayer(function(marker) {
                marker.off(this._childMarkerEventHandlers, this);
                delete marker.__parent;
            }, this);

            if (this._map) {
                // Reset _topClusterLevel and the DistanceGrids
                this._generateInitialClusters();
            }

            return this;
        },

        // Override FeatureGroup.getBounds as it doesn't work
        getBounds: function() {
            var bounds = new L.LatLngBounds();

            if (this._topClusterLevel) {
                bounds.extend(this._topClusterLevel._bounds);
            }

            for (var i = this._needsClustering.length - 1; i >= 0; i--) {
                bounds.extend(this._needsClustering[i].getLatLng());
            }

            bounds.extend(this._nonPointGroup.getBounds());

            return bounds;
        },

        // Overrides LayerGroup.eachLayer
        eachLayer: function(method, context) {
            var markers = this._needsClustering.slice(),
                needsRemoving = this._needsRemoving,
                thisNeedsRemoving, i, j;

            if (this._topClusterLevel) {
                this._topClusterLevel.getAllChildMarkers(markers);
            }

            for (i = markers.length - 1; i >= 0; i--) {
                thisNeedsRemoving = true;

                for (j = needsRemoving.length - 1; j >= 0; j--) {
                    if (needsRemoving[j].layer === markers[i]) {
                        thisNeedsRemoving = false;
                        break;
                    }
                }

                if (thisNeedsRemoving) {
                    method.call(context, markers[i]);
                }
            }

            this._nonPointGroup.eachLayer(method, context);
        },

        // Overrides LayerGroup.getLayers
        getLayers: function() {
            var layers = [];
            this.eachLayer(function(l) {
                layers.push(l);
            });
            return layers;
        },

        // Overrides LayerGroup.getLayer, WARNING: Really bad performance
        getLayer: function(id) {
            var result = null;

            id = parseInt(id, 10);

            this.eachLayer(function(l) {
                if (L.stamp(l) === id) {
                    result = l;
                }
            });

            return result;
        },

        // Returns true if the given layer is in this MarkerClusterGroup
        hasLayer: function(layer) {
            if (!layer) {
                return false;
            }

            var i, anArray = this._needsClustering;

            for (i = anArray.length - 1; i >= 0; i--) {
                if (anArray[i] === layer) {
                    return true;
                }
            }

            anArray = this._needsRemoving;
            for (i = anArray.length - 1; i >= 0; i--) {
                if (anArray[i].layer === layer) {
                    return false;
                }
            }

            return !!(layer.__parent && layer.__parent._group === this) || this._nonPointGroup.hasLayer(layer);
        },

        // Zoom down to show the given layer (spiderfying if necessary) then calls the callback
        zoomToShowLayer: function(layer, callback) {

            if (typeof callback !== 'function') {
                callback = function() {
                };
            }
    // Zoom down to show the given layer (spiderfying if necessary) then calls the callback
    zoomToShowLayer: function (layer, callback) {
      if (typeof callback !== 'function') {
        callback = function () {
        }
      }

            var showMarker = function() {
                if ((layer._icon || layer.__parent._icon) && !this._inZoomAnimation) {
                    this._map.off('moveend', showMarker, this);
                    this.off('animationend', showMarker, this);
      var showMarker = function () {
        if ((layer._icon || layer.__parent._icon) && !this._inZoomAnimation) {
          this._map.off('moveend', showMarker, this)
          this.off('animationend', showMarker, this)

                    if (layer._icon) {
                        callback();
                    } else if (layer.__parent._icon) {
                        this.once('spiderfied', callback, this);
                        layer.__parent.spiderfy();
                    }
                }
            };
          if (layer._icon) {
            callback()
          } else if (layer.__parent._icon) {
            this.once('spiderfied', callback, this)
            layer.__parent.spiderfy()
          }
        }
      }

            if (layer._icon && this._map.getBounds().contains(layer.getLatLng())) {
                // Layer is visible ond on screen, immediate return
                callback();
            } else if (layer.__parent._zoom < Math.round(this._map._zoom)) {
                // Layer should be visible at this zoom level. It must not be on screen so just pan over to it
                this._map.on('moveend', showMarker, this);
                this._map.panTo(layer.getLatLng());
            } else {
                this._map.on('moveend', showMarker, this);
                this.on('animationend', showMarker, this);
                layer.__parent.zoomToBounds();
            }
        },
      if (layer._icon && this._map.getBounds().contains(layer.getLatLng())) {
        // Layer is visible ond on screen, immediate return
        callback()
      } else if (layer.__parent._zoom < Math.round(this._map._zoom)) {
        // Layer should be visible at this zoom level. It must not be on screen so just pan over to it
        this._map.on('moveend', showMarker, this)
        this._map.panTo(layer.getLatLng())
      } else {
        this._map.on('moveend', showMarker, this)
        this.on('animationend', showMarker, this)
        layer.__parent.zoomToBounds()
      }
    },

        // Overrides FeatureGroup.onAdd
        onAdd: function(map) {
            this._map = map;
            var i, l, layer;
    // Overrides FeatureGroup.onAdd
    onAdd: function (map) {
      this._map = map
      var i, l, layer

            if (!isFinite(this._map.getMaxZoom())) {
                throw "Map has no maxZoom specified";
            }
      if (!isFinite(this._map.getMaxZoom())) {
          // eslint-disable-next-line no-throw-literal
        throw 'Map has no maxZoom specified'
      }

            this._featureGroup.addTo(map);
            this._nonPointGroup.addTo(map);
      this._featureGroup.addTo(map)
      this._nonPointGroup.addTo(map)

            if (!this._gridClusters) {
                this._generateInitialClusters();
            }
      if (!this._gridClusters) {
        this._generateInitialClusters()
      }

            this._maxLat = map.options.crs.projection.MAX_LATITUDE;
      this._maxLat = map.options.crs.projection.MAX_LATITUDE

            // Restore all the positions as they are in the MCG before removing them
            for (i = 0, l = this._needsRemoving.length; i < l; i++) {
                layer = this._needsRemoving[i];
                layer.newlatlng = layer.layer._latlng;
                layer.layer._latlng = layer.latlng;
            }
            // Remove them, then restore their new positions
            for (i = 0, l = this._needsRemoving.length; i < l; i++) {
                layer = this._needsRemoving[i];
                this._removeLayer(layer.layer, true);
                layer.layer._latlng = layer.newlatlng;
            }
            this._needsRemoving = [];
      // Restore all the positions as they are in the MCG before removing them
      for (i = 0, l = this._needsRemoving.length; i < l; i++) {
        layer = this._needsRemoving[i]
        layer.newlatlng = layer.layer._latlng
        layer.layer._latlng = layer.latlng
      }
      // Remove them, then restore their new positions
      for (i = 0, l = this._needsRemoving.length; i < l; i++) {
        layer = this._needsRemoving[i]
        this._removeLayer(layer.layer, true)
        layer.layer._latlng = layer.newlatlng
      }
      this._needsRemoving = []

            // Remember the current zoom level and bounds
            this._zoom = Math.round(this._map._zoom);
            this._currentShownBounds = this._getExpandedVisibleBounds();
      // Remember the current zoom level and bounds
      this._zoom = Math.round(this._map._zoom)
      this._currentShownBounds = this._getExpandedVisibleBounds()

            this._map.on('zoomend', this._zoomEnd, this);
            this._map.on('moveend', this._moveEnd, this);
      this._map.on('zoomend', this._zoomEnd, this)
      this._map.on('moveend', this._moveEnd, this)

            if (this._spiderfierOnAdd) { // TODO FIXME: Not sure how to have spiderfier add something on here nicely
                this._spiderfierOnAdd();
            }
      if (this._spiderfierOnAdd) { // TODO FIXME: Not sure how to have spiderfier add something on here nicely
        this._spiderfierOnAdd()
      }

            this._bindEvents();
      this._bindEvents()

            // Actually add our markers to the map:
            l = this._needsClustering;
            this._needsClustering = [];
            this.addLayers(l, true);
        },
      // Actually add our markers to the map:
      l = this._needsClustering
      this._needsClustering = []
      this.addLayers(l, true)
    },

        // Overrides FeatureGroup.onRemove
        onRemove: function(map) {
            map.off('zoomend', this._zoomEnd, this);
            map.off('moveend', this._moveEnd, this);
    // Overrides FeatureGroup.onRemove
    onRemove: function (map) {
      map.off('zoomend', this._zoomEnd, this)
      map.off('moveend', this._moveEnd, this)

            this._unbindEvents();
      this._unbindEvents()

            // In case we are in a cluster animation
            this._map._mapPane.className = this._map._mapPane.className.replace(' leaflet-cluster-anim', '');
      // In case we are in a cluster animation
      this._map._mapPane.className = this._map._mapPane.className.replace(' leaflet-cluster-anim', '')

            if (this._spiderfierOnRemove) { // TODO FIXME: Not sure how to have spiderfier add something on here nicely
                this._spiderfierOnRemove();
            }
      if (this._spiderfierOnRemove) { // TODO FIXME: Not sure how to have spiderfier add something on here nicely
        this._spiderfierOnRemove()
      }

            delete this._maxLat;
      delete this._maxLat

            // Clean up all the layers we added to the map
            this._hideCoverage();
            this._featureGroup.remove();
            this._nonPointGroup.remove();
      // Clean up all the layers we added to the map
      this._hideCoverage()
      this._featureGroup.remove()
      this._nonPointGroup.remove()

            this._featureGroup.clearLayers();
      this._featureGroup.clearLayers()

            this._map = null;
        },
      this._map = null
    },

        getVisibleParent: function(marker) {
            var vMarker = marker;
            while (vMarker && !vMarker._icon) {
                vMarker = vMarker.__parent;
            }
            return vMarker || null;
        },
    getVisibleParent: function (marker) {
      var vMarker = marker
      while (vMarker && !vMarker._icon) {
        vMarker = vMarker.__parent
      }
      return vMarker || null
    },

        // Remove the given object from the given array
        _arraySplice: function(anArray, obj) {
            for (var i = anArray.length - 1; i >= 0; i--) {
                if (anArray[i] === obj) {
                    anArray.splice(i, 1);
                    return true;
                }
            }
        },
    // Remove the given object from the given array
    _arraySplice: function (anArray, obj) {
      for (var i = anArray.length - 1; i >= 0; i--) {
        if (anArray[i] === obj) {
          anArray.splice(i, 1)
          return true
        }
      }
    },

        /**
    /**
         * Removes a marker from all _gridUnclustered zoom levels, starting at the supplied zoom.
         * @param marker to be removed from _gridUnclustered.
         * @param z integer bottom start zoom level (included)
         * @private
         */
        _removeFromGridUnclustered: function(marker, z) {
            var map = this._map,
                gridUnclustered = this._gridUnclustered,
                minZoom = Math.floor(this._map.getMinZoom());
    _removeFromGridUnclustered: function (marker, z) {
      var map = this._map
      var gridUnclustered = this._gridUnclustered
      var minZoom = Math.floor(this._map.getMinZoom())

            for (; z >= minZoom; z--) {
                if (!gridUnclustered[z].removeObject(marker, map.project(marker.getLatLng(), z))) {
                    break;
                }
      for (; z >= minZoom; z--) {
        if (!gridUnclustered[z].removeObject(marker, map.project(marker.getLatLng(), z))) {
          break
        }
      }
    },

    _childMarkerDragStart: function (e) {
      e.target.__dragStart = e.target._latlng
    },

    _childMarkerMoved: function (e) {
      if (!this._ignoreMove && !e.target.__dragStart) {
        var isPopupOpen = e.target._popup && e.target._popup.isOpen()

        this._moveChild(e.target, e.oldLatLng, e.latlng)

        if (isPopupOpen) {
          e.target.openPopup()
        }
      }
    },

    _moveChild: function (layer, from, to) {
      layer._latlng = from
      this.removeLayer(layer)

      layer._latlng = to
      this.addLayer(layer)
    },

    _childMarkerDragEnd: function (e) {
      var dragStart = e.target.__dragStart
      delete e.target.__dragStart
      if (dragStart) {
        this._moveChild(e.target, dragStart, e.target._latlng)
      }
    },

    // Internal function for removing a marker from everything.
    // dontUpdateMap: set to true if you will handle updating the map manually (for bulk functions)
    _removeLayer: function (marker, removeFromDistanceGrid, dontUpdateMap) {
      var gridClusters = this._gridClusters
      var gridUnclustered = this._gridUnclustered
      var fg = this._featureGroup
      var map = this._map
      var minZoom = Math.floor(this._map.getMinZoom())

      // Remove the marker from distance clusters it might be in
      if (removeFromDistanceGrid) {
        this._removeFromGridUnclustered(marker, this._maxZoom)
      }

      // Work our way up the clusters removing them as we go if required
      var cluster = marker.__parent
      var markers = cluster._markers
      var otherMarker

      // Remove the marker from the immediate parents marker list
      this._arraySplice(markers, marker)

      while (cluster) {
        cluster._childCount--
        cluster._boundsNeedUpdate = true

        if (cluster._zoom < minZoom) {
          // Top level, do nothing
          break
        } else if (removeFromDistanceGrid && cluster._childCount <= 1) { // Cluster no longer required
          // We need to push the other marker up to the parent
          otherMarker = cluster._markers[0] === marker ? cluster._markers[1] : cluster._markers[0]

          // Update distance grid
          gridClusters[cluster._zoom].removeObject(cluster, map.project(cluster._cLatLng, cluster._zoom))
          gridUnclustered[cluster._zoom].addObject(otherMarker, map.project(otherMarker.getLatLng(), cluster._zoom))

          // Move otherMarker up to parent
          this._arraySplice(cluster.__parent._childClusters, cluster)
          cluster.__parent._markers.push(otherMarker)
          otherMarker.__parent = cluster.__parent

          if (cluster._icon) {
            // Cluster is currently on the map, need to put the marker on the map instead
            fg.removeLayer(cluster)
            if (!dontUpdateMap) {
              fg.addLayer(otherMarker)
            }
        },
          }
        } else {
          cluster._iconNeedsUpdate = true
        }

        _childMarkerDragStart: function(e) {
            e.target.__dragStart = e.target._latlng;
        },
        cluster = cluster.__parent
      }

        _childMarkerMoved: function(e) {
            if (!this._ignoreMove && !e.target.__dragStart) {
                var isPopupOpen = e.target._popup && e.target._popup.isOpen();
      delete marker.__parent
    },

                this._moveChild(e.target, e.oldLatLng, e.latlng);
    _isOrIsParent: function (el, oel) {
      while (oel) {
        if (el === oel) {
          return true
        }
        oel = oel.parentNode
      }
      return false
    },

                if (isPopupOpen) {
                    e.target.openPopup();
                }
            }
        },
    // Override L.Evented.fire
    fire: function (type, data, propagate) {
      if (data && data.layer instanceof L.MarkerCluster) {
        // Prevent multiple clustermouseover/off events if the icon is made up of stacked divs (Doesn't work in ie <= 8, no relatedTarget)
        if (data.originalEvent && this._isOrIsParent(data.layer._icon, data.originalEvent.relatedTarget)) {
          return
        }
        type = 'cluster' + type
      }

        _moveChild: function(layer, from, to) {
            layer._latlng = from;
            this.removeLayer(layer);
      L.FeatureGroup.prototype.fire.call(this, type, data, propagate)
    },

            layer._latlng = to;
            this.addLayer(layer);
        },
    // Override L.Evented.listens
    listens: function (type, propagate) {
      return L.FeatureGroup.prototype.listens.call(this, type, propagate) || L.FeatureGroup.prototype.listens.call(this, 'cluster' + type, propagate)
    },

        _childMarkerDragEnd: function(e) {
            var dragStart = e.target.__dragStart;
            delete e.target.__dragStart;
            if (dragStart) {
                this._moveChild(e.target, dragStart, e.target._latlng);
            }
        },
    // Default functionality
    _defaultIconCreateFunction: function (cluster) {
      var childCount = cluster.getChildCount()

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

        // Internal function for removing a marker from everything.
        // dontUpdateMap: set to true if you will handle updating the map manually (for bulk functions)
        _removeLayer: function(marker, removeFromDistanceGrid, dontUpdateMap) {
            var gridClusters = this._gridClusters,
                gridUnclustered = this._gridUnclustered,
                fg = this._featureGroup,
                map = this._map,
                minZoom = Math.floor(this._map.getMinZoom());
      return new L.DivIcon({
        html: '<div><span>' + childCount + '</span></div>',
        className: 'marker-cluster' + c,
        iconSize: new L.Point(40, 40)
      })
    },

            // Remove the marker from distance clusters it might be in
            if (removeFromDistanceGrid) {
                this._removeFromGridUnclustered(marker, this._maxZoom);
            }
    _bindEvents: function () {
      var map = this._map
      var spiderfyOnMaxZoom = this.options.spiderfyOnMaxZoom
      var showCoverageOnHover = this.options.showCoverageOnHover
      var zoomToBoundsOnClick = this.options.zoomToBoundsOnClick

            // Work our way up the clusters removing them as we go if required
            var cluster = marker.__parent,
                markers = cluster._markers,
                otherMarker;
      // Zoom on cluster click or spiderfy if we are at the lowest level
      if (spiderfyOnMaxZoom || zoomToBoundsOnClick) {
        this.on('clusterclick', this._zoomOrSpiderfy, this)
      }

            // Remove the marker from the immediate parents marker list
            this._arraySplice(markers, marker);
      // Show convex hull (boundary) polygon on mouse over
      if (showCoverageOnHover) {
        this.on('clustermouseover', this._showCoverage, this)
        this.on('clustermouseout', this._hideCoverage, this)
        map.on('zoomend', this._hideCoverage, this)
      }
    },

            while (cluster) {
                cluster._childCount--;
                cluster._boundsNeedUpdate = true;
    _zoomOrSpiderfy: function (e) {
      var cluster = e.layer
      var bottomCluster = cluster

                if (cluster._zoom < minZoom) {
                    // Top level, do nothing
                    break;
                } else if (removeFromDistanceGrid && cluster._childCount <= 1) { // Cluster no longer required
                    // We need to push the other marker up to the parent
                    otherMarker = cluster._markers[0] === marker ? cluster._markers[1] : cluster._markers[0];
      while (bottomCluster._childClusters.length === 1) {
        bottomCluster = bottomCluster._childClusters[0]
      }

                    // Update distance grid
                    gridClusters[cluster._zoom].removeObject(cluster, map.project(cluster._cLatLng, cluster._zoom));
                    gridUnclustered[cluster._zoom].addObject(otherMarker, map.project(otherMarker.getLatLng(), cluster._zoom));

                    // Move otherMarker up to parent
                    this._arraySplice(cluster.__parent._childClusters, cluster);
                    cluster.__parent._markers.push(otherMarker);
                    otherMarker.__parent = cluster.__parent;

                    if (cluster._icon) {
                        // Cluster is currently on the map, need to put the marker on the map instead
                        fg.removeLayer(cluster);
                        if (!dontUpdateMap) {
                            fg.addLayer(otherMarker);
                        }
                    }
                } else {
                    cluster._iconNeedsUpdate = true;
                }

                cluster = cluster.__parent;
            }

            delete marker.__parent;
        },

        _isOrIsParent: function(el, oel) {
            while (oel) {
                if (el === oel) {
                    return true;
                }
                oel = oel.parentNode;
            }
            return false;
        },

        // Override L.Evented.fire
        fire: function(type, data, propagate) {
            if (data && data.layer instanceof L.MarkerCluster) {
                // Prevent multiple clustermouseover/off events if the icon is made up of stacked divs (Doesn't work in ie <= 8, no relatedTarget)
                if (data.originalEvent && this._isOrIsParent(data.layer._icon, data.originalEvent.relatedTarget)) {
                    return;
                }
                type = 'cluster' + type;
            }

            L.FeatureGroup.prototype.fire.call(this, type, data, propagate);
        },

        // Override L.Evented.listens
        listens: function(type, propagate) {
            return L.FeatureGroup.prototype.listens.call(this, type, propagate) || L.FeatureGroup.prototype.listens.call(this, 'cluster' + type, propagate);
        },

        // Default functionality
        _defaultIconCreateFunction: 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)
            });
        },

        _bindEvents: function() {
            var map = this._map,
                spiderfyOnMaxZoom = this.options.spiderfyOnMaxZoom,
                showCoverageOnHover = this.options.showCoverageOnHover,
                zoomToBoundsOnClick = this.options.zoomToBoundsOnClick;

            // Zoom on cluster click or spiderfy if we are at the lowest level
            if (spiderfyOnMaxZoom || zoomToBoundsOnClick) {
                this.on('clusterclick', this._zoomOrSpiderfy, this);
            }

            // Show convex hull (boundary) polygon on mouse over
            if (showCoverageOnHover) {
                this.on('clustermouseover', this._showCoverage, this);
                this.on('clustermouseout', this._hideCoverage, this);
                map.on('zoomend', this._hideCoverage, this);
            }
        },

        _zoomOrSpiderfy: function(e) {
            var cluster = e.layer,
                bottomCluster = cluster;

            while (bottomCluster._childClusters.length === 1) {
                bottomCluster = bottomCluster._childClusters[0];
            }

            if (bottomCluster._zoom === this._maxZoom &&
      if (bottomCluster._zoom === this._maxZoom &&
                bottomCluster._childCount === cluster._childCount &&
                this.options.spiderfyOnMaxZoom) {
        //  All child markers are contained in a single cluster from this._maxZoom to this cluster.
        cluster.spiderfy()
      } else if (this.options.zoomToBoundsOnClick) {
        cluster.zoomToBounds()
      }

                //  All child markers are contained in a single cluster from this._maxZoom to this cluster.
                cluster.spiderfy();
            } else if (this.options.zoomToBoundsOnClick) {
                cluster.zoomToBounds();
            }
      //  Focus the map again for keyboard users.
      if (e.originalEvent && e.originalEvent.keyCode === 13) {
        this._map._container.focus()
      }
    },

            //  Focus the map again for keyboard users.
            if (e.originalEvent && e.originalEvent.keyCode === 13) {
                this._map._container.focus();
            }
        },
    _showCoverage: function (e) {
      var map = this._map
      if (this._inZoomAnimation) {
        return
      }
      if (this._shownPolygon) {
        map.removeLayer(this._shownPolygon)
      }
      if (e.layer.getChildCount() > 2 && e.layer !== this._spiderfied) {
        this._shownPolygon = new L.Polygon(e.layer.getConvexHull(), this.options.polygonOptions)
        map.addLayer(this._shownPolygon)
      }
    },

        _showCoverage: function(e) {
            var map = this._map;
            if (this._inZoomAnimation) {
                return;
            }
            if (this._shownPolygon) {
                map.removeLayer(this._shownPolygon);
            }
            if (e.layer.getChildCount() > 2 && e.layer !== this._spiderfied) {
                this._shownPolygon = new L.Polygon(e.layer.getConvexHull(), this.options.polygonOptions);
                map.addLayer(this._shownPolygon);
            }
        },
    _hideCoverage: function () {
      if (this._shownPolygon) {
        this._map.removeLayer(this._shownPolygon)
        this._shownPolygon = null
      }
    },

        _hideCoverage: function() {
            if (this._shownPolygon) {
                this._map.removeLayer(this._shownPolygon);
                this._shownPolygon = null;
            }
        },
    _unbindEvents: function () {
      var spiderfyOnMaxZoom = this.options.spiderfyOnMaxZoom
      var showCoverageOnHover = this.options.showCoverageOnHover
      var zoomToBoundsOnClick = this.options.zoomToBoundsOnClick
      var map = this._map

        _unbindEvents: function() {
            var spiderfyOnMaxZoom = this.options.spiderfyOnMaxZoom,
                showCoverageOnHover = this.options.showCoverageOnHover,
                zoomToBoundsOnClick = this.options.zoomToBoundsOnClick,
                map = this._map;
      if (spiderfyOnMaxZoom || zoomToBoundsOnClick) {
        this.off('clusterclick', this._zoomOrSpiderfy, this)
      }
      if (showCoverageOnHover) {
        this.off('clustermouseover', this._showCoverage, this)
        this.off('clustermouseout', this._hideCoverage, this)
        map.off('zoomend', this._hideCoverage, this)
      }
    },

            if (spiderfyOnMaxZoom || zoomToBoundsOnClick) {
                this.off('clusterclick', this._zoomOrSpiderfy, this);
            }
            if (showCoverageOnHover) {
                this.off('clustermouseover', this._showCoverage, this);
                this.off('clustermouseout', this._hideCoverage, this);
                map.off('zoomend', this._hideCoverage, this);
            }
        },
    _zoomEnd: function () {
      if (!this._map) { // May have been removed from the map by a zoomEnd handler
        return
      }
      this._mergeSplitClusters()

        _zoomEnd: function() {
            if (!this._map) { // May have been removed from the map by a zoomEnd handler
                return;
            }
            this._mergeSplitClusters();
      this._zoom = Math.round(this._map._zoom)
      this._currentShownBounds = this._getExpandedVisibleBounds()
    },

            this._zoom = Math.round(this._map._zoom);
            this._currentShownBounds = this._getExpandedVisibleBounds();
        },
    _moveEnd: function () {
      if (this._inZoomAnimation) {
        return
      }

        _moveEnd: function() {
            if (this._inZoomAnimation) {
                return;
            }
      var newBounds = this._getExpandedVisibleBounds()

            var newBounds = this._getExpandedVisibleBounds();
      this._topClusterLevel._recursivelyRemoveChildrenFromMap(this._currentShownBounds, Math.floor(this._map.getMinZoom()), this._zoom, newBounds)
      this._topClusterLevel._recursivelyAddChildrenToMap(null, Math.round(this._map._zoom), newBounds)

            this._topClusterLevel._recursivelyRemoveChildrenFromMap(this._currentShownBounds, Math.floor(this._map.getMinZoom()), this._zoom, newBounds);
            this._topClusterLevel._recursivelyAddChildrenToMap(null, Math.round(this._map._zoom), newBounds);
      this._currentShownBounds = newBounds
    },

            this._currentShownBounds = newBounds;
            return;
        },
    _generateInitialClusters: function () {
      var maxZoom = Math.ceil(this._map.getMaxZoom())
      var minZoom = Math.floor(this._map.getMinZoom())
      var radius = this.options.maxClusterRadius
      var radiusFn = radius

        _generateInitialClusters: function() {
            var maxZoom = Math.ceil(this._map.getMaxZoom()),
                minZoom = Math.floor(this._map.getMinZoom()),
                radius = this.options.maxClusterRadius,
                radiusFn = radius;
      // If we just set maxClusterRadius to a single number, we need to create
      // a simple function to return that number. Otherwise, we just have to
      // use the function we've passed in.
      if (typeof radius !== 'function') {
        radiusFn = function () {
          return radius
        }
      }

            // If we just set maxClusterRadius to a single number, we need to create
            // a simple function to return that number. Otherwise, we just have to
            // use the function we've passed in.
            if (typeof radius !== "function") {
                radiusFn = function() {
                    return radius;
                };
            }
      if (this.options.disableClusteringAtZoom !== null) {
        maxZoom = this.options.disableClusteringAtZoom - 1
      }
      this._maxZoom = maxZoom
      this._gridClusters = {}
      this._gridUnclustered = {}

            if (this.options.disableClusteringAtZoom !== null) {
                maxZoom = this.options.disableClusteringAtZoom - 1;
            }
            this._maxZoom = maxZoom;
            this._gridClusters = {};
            this._gridUnclustered = {};
      // Set up DistanceGrids for each zoom
      for (var zoom = maxZoom; zoom >= minZoom; zoom--) {
        this._gridClusters[zoom] = new L.DistanceGrid(radiusFn(zoom))
        this._gridUnclustered[zoom] = new L.DistanceGrid(radiusFn(zoom))
      }

            // Set up DistanceGrids for each zoom
            for (var zoom = maxZoom; zoom >= minZoom; zoom--) {
                this._gridClusters[zoom] = new L.DistanceGrid(radiusFn(zoom));
                this._gridUnclustered[zoom] = new L.DistanceGrid(radiusFn(zoom));
            }
      //  Instantiate the appropriate L.MarkerCluster class (animated or not).
      this._topClusterLevel = new this._markerCluster(this, minZoom - 1)
    },

            //  Instantiate the appropriate L.MarkerCluster class (animated or not).
            this._topClusterLevel = new this._markerCluster(this, minZoom - 1);
        },
    // Zoom: Zoom to start adding at (Pass this._maxZoom to start at the bottom)
    _addLayer: function (layer, zoom) {
      var gridClusters = this._gridClusters
      var gridUnclustered = this._gridUnclustered
      var minZoom = Math.floor(this._map.getMinZoom())
      var markerPoint; var z

        // Zoom: Zoom to start adding at (Pass this._maxZoom to start at the bottom)
        _addLayer: function(layer, zoom) {
            var gridClusters = this._gridClusters,
                gridUnclustered = this._gridUnclustered,
                minZoom = Math.floor(this._map.getMinZoom()),
                markerPoint, z;
      if (this.options.singleMarkerMode) {
        this._overrideMarkerIcon(layer)
      }

            if (this.options.singleMarkerMode) {
                this._overrideMarkerIcon(layer);
            }
      layer.on(this._childMarkerEventHandlers, this)

            layer.on(this._childMarkerEventHandlers, this);
      // Find the lowest zoom level to slot this one in
      for (; zoom >= minZoom; zoom--) {
        markerPoint = this._map.project(layer.getLatLng(), zoom) //  calculate pixel position

            // Find the lowest zoom level to slot this one in
            for (; zoom >= minZoom; zoom--) {
                markerPoint = this._map.project(layer.getLatLng(), zoom); //  calculate pixel position
        // Try find a cluster close by
        var closest = gridClusters[zoom].getNearObject(markerPoint)
        if (closest) {
          closest._addChild(layer)
          layer.__parent = closest
          return
        }

                // Try find a cluster close by
                var closest = gridClusters[zoom].getNearObject(markerPoint);
                if (closest) {
                    closest._addChild(layer);
                    layer.__parent = closest;
                    return;
                }
        // Try find a marker close by to form a new cluster with
        closest = gridUnclustered[zoom].getNearObject(markerPoint)
        if (closest) {
          var parent = closest.__parent
          if (parent) {
            this._removeLayer(closest, false)
          }

                // Try find a marker close by to form a new cluster with
                closest = gridUnclustered[zoom].getNearObject(markerPoint);
                if (closest) {
                    var parent = closest.__parent;
                    if (parent) {
                        this._removeLayer(closest, false);
                    }
          // Create new cluster with these 2 in it

                    // Create new cluster with these 2 in it
          var newCluster = new this._markerCluster(this, zoom, closest, layer)
          gridClusters[zoom].addObject(newCluster, this._map.project(newCluster._cLatLng, zoom))
          closest.__parent = newCluster
          layer.__parent = newCluster

                    var newCluster = new this._markerCluster(this, zoom, closest, layer);
                    gridClusters[zoom].addObject(newCluster, this._map.project(newCluster._cLatLng, zoom));
                    closest.__parent = newCluster;
                    layer.__parent = newCluster;
          // First create any new intermediate parent clusters that don't exist
          var lastParent = newCluster
          for (z = zoom - 1; z > parent._zoom; z--) {
            lastParent = new this._markerCluster(this, z, lastParent)
            gridClusters[z].addObject(lastParent, this._map.project(closest.getLatLng(), z))
          }
          parent._addChild(lastParent)

                    // First create any new intermediate parent clusters that don't exist
                    var lastParent = newCluster;
                    for (z = zoom - 1; z > parent._zoom; z--) {
                        lastParent = new this._markerCluster(this, z, lastParent);
                        gridClusters[z].addObject(lastParent, this._map.project(closest.getLatLng(), z));
                    }
                    parent._addChild(lastParent);
          // Remove closest from this zoom level and any above that it is in, replace with newCluster
          this._removeFromGridUnclustered(closest, zoom)

                    // Remove closest from this zoom level and any above that it is in, replace with newCluster
                    this._removeFromGridUnclustered(closest, zoom);
          return
        }

                    return;
                }
        // Didn't manage to cluster in at this zoom, record us as a marker here and continue upwards
        gridUnclustered[zoom].addObject(layer, markerPoint)
      }

                // Didn't manage to cluster in at this zoom, record us as a marker here and continue upwards
                gridUnclustered[zoom].addObject(layer, markerPoint);
            }
      // Didn't get in anything, add us to the top
      this._topClusterLevel._addChild(layer)
      layer.__parent = this._topClusterLevel
    },

            // Didn't get in anything, add us to the top
            this._topClusterLevel._addChild(layer);
            layer.__parent = this._topClusterLevel;
            return;
        },

        /**
    /**
         * Refreshes the icon of all "dirty" visible clusters.
         * Non-visible "dirty" clusters will be updated when they are added to the map.
         * @private
         */
        _refreshClustersIcons: function() {
            this._featureGroup.eachLayer(function(c) {
                if (c instanceof L.MarkerCluster && c._iconNeedsUpdate) {
                    c._updateIcon();
                }
            });
        },
    _refreshClustersIcons: function () {
      this._featureGroup.eachLayer(function (c) {
        if (c instanceof L.MarkerCluster && c._iconNeedsUpdate) {
          c._updateIcon()
        }
      })
    },

        // Enqueue code to fire after the marker expand/contract has happened
        _enqueue: function(fn) {
            this._queue.push(fn);
            if (!this._queueTimeout) {
                this._queueTimeout = setTimeout(L.bind(this._processQueue, this), 300);
            }
        },
        _processQueue: function() {
            for (var i = 0; i < this._queue.length; i++) {
                this._queue[i].call(this);
            }
            this._queue.length = 0;
            clearTimeout(this._queueTimeout);
            this._queueTimeout = null;
        },
    // Enqueue code to fire after the marker expand/contract has happened
    _enqueue: function (fn) {
      this._queue.push(fn)
      if (!this._queueTimeout) {
        this._queueTimeout = setTimeout(L.bind(this._processQueue, this), 300)
      }
    },
    _processQueue: function () {
      for (var i = 0; i < this._queue.length; i++) {
        this._queue[i].call(this)
      }
      this._queue.length = 0
      clearTimeout(this._queueTimeout)
      this._queueTimeout = null
    },

        // Merge and split any existing clusters that are too big or small
        _mergeSplitClusters: function() {
            var mapZoom = Math.round(this._map._zoom);
    // Merge and split any existing clusters that are too big or small
    _mergeSplitClusters: function () {
      var mapZoom = Math.round(this._map._zoom)

            // In case we are starting to split before the animation finished
            this._processQueue();
      // In case we are starting to split before the animation finished
      this._processQueue()

            if (this._zoom < mapZoom && this._currentShownBounds.intersects(this._getExpandedVisibleBounds())) { // Zoom in, split
                this._animationStart();
                // Remove clusters now off screen
                this._topClusterLevel._recursivelyRemoveChildrenFromMap(this._currentShownBounds, Math.floor(this._map.getMinZoom()), this._zoom, this._getExpandedVisibleBounds());
      if (this._zoom < mapZoom && this._currentShownBounds.intersects(this._getExpandedVisibleBounds())) { // Zoom in, split
        this._animationStart()
        // Remove clusters now off screen
        this._topClusterLevel._recursivelyRemoveChildrenFromMap(this._currentShownBounds, Math.floor(this._map.getMinZoom()), this._zoom, this._getExpandedVisibleBounds())

                this._animationZoomIn(this._zoom, mapZoom);
        this._animationZoomIn(this._zoom, mapZoom)
      } else if (this._zoom > mapZoom) { // Zoom out, merge
        this._animationStart()

            } else if (this._zoom > mapZoom) { // Zoom out, merge
                this._animationStart();
        this._animationZoomOut(this._zoom, mapZoom)
      } else {
        this._moveEnd()
      }
    },

                this._animationZoomOut(this._zoom, mapZoom);
            } else {
                this._moveEnd();
            }
        },
    // Gets the maps visible bounds expanded in each direction by the size of the screen (so the user cannot see an area we do not cover in one pan)
    _getExpandedVisibleBounds: function () {
      if (!this.options.removeOutsideVisibleBounds) {
        return this._mapBoundsInfinite
      } else if (L.Browser.mobile) {
        return this._checkBoundsMaxLat(this._map.getBounds())
      }

        // Gets the maps visible bounds expanded in each direction by the size of the screen (so the user cannot see an area we do not cover in one pan)
        _getExpandedVisibleBounds: function() {
            if (!this.options.removeOutsideVisibleBounds) {
                return this._mapBoundsInfinite
            } else if (L.Browser.mobile) {
                return this._checkBoundsMaxLat(this._map.getBounds())
            }
      return this._checkBoundsMaxLat(this._map.getBounds().pad(1)) //  Padding expands the bounds by its own dimensions but scaled with the given factor.
    },

            return this._checkBoundsMaxLat(this._map.getBounds().pad(1)) //  Padding expands the bounds by its own dimensions but scaled with the given factor.
        },

        /**
    /**
         * Expands the latitude to Infinity (or -Infinity) if the input bounds reach the map projection maximum defined latitude
         * (in the case of Web/Spherical Mercator, it is 85.0511287798 / see https:// en.wikipedia.org/wiki/Web_Mercator#Formulas).
         * Otherwise, the removeOutsideVisibleBounds option will remove markers beyond that limit, whereas the same markers without
@@ -1099,691 +1090,689 @@
         * @returns {L.LatLngBounds}
         * @private
         */
        _checkBoundsMaxLat: function(bounds) {
            var maxLat = this._maxLat
    _checkBoundsMaxLat: function (bounds) {
      var maxLat = this._maxLat

            if (maxLat !== undefined) {
                if (bounds.getNorth() >= maxLat) {
                    bounds._northEast.lat = Infinity
                }
                if (bounds.getSouth() <= -maxLat) {
                    bounds._southWest.lat = -Infinity
                }
            }
      if (maxLat !== undefined) {
        if (bounds.getNorth() >= maxLat) {
          bounds._northEast.lat = Infinity
        }
        if (bounds.getSouth() <= -maxLat) {
          bounds._southWest.lat = -Infinity
        }
      }

            return bounds
        },
      return bounds
    },

        // Shared animation code
        _animationAddLayerNonAnimated: function(layer, newCluster) {
            if (newCluster === layer) {
                this._featureGroup.addLayer(layer)
            } else if (newCluster._childCount === 2) {
                newCluster._addToMap()
    // Shared animation code
    _animationAddLayerNonAnimated: function (layer, newCluster) {
      if (newCluster === layer) {
        this._featureGroup.addLayer(layer)
      } else if (newCluster._childCount === 2) {
        newCluster._addToMap()

                var markers = newCluster.getAllChildMarkers()
                this._featureGroup.removeLayer(markers[0])
                this._featureGroup.removeLayer(markers[1])
            } else {
                newCluster._updateIcon()
            }
        },
        var markers = newCluster.getAllChildMarkers()
        this._featureGroup.removeLayer(markers[0])
        this._featureGroup.removeLayer(markers[1])
      } else {
        newCluster._updateIcon()
      }
    },

        /**
    /**
         * Extracts individual (i.e. non-group) layers from a Layer Group.
         * @param group to extract layers from.
         * @param output {Array} in which to store the extracted layers.
         * @returns {*|Array}
         * @private
         */
        _extractNonGroupLayers: function(group, output) {
            var layers = group.getLayers(),
                i = 0,
                layer
    _extractNonGroupLayers: function (group, output) {
      var layers = group.getLayers()
      var i = 0
      var layer

            output = output || []
      output = output || []

            for (; i < layers.length; i++) {
                layer = layers[i]
      for (; i < layers.length; i++) {
        layer = layers[i]

                if (layer instanceof L.LayerGroup) {
                    this._extractNonGroupLayers(layer, output)
                    continue
                }
        if (layer instanceof L.LayerGroup) {
          this._extractNonGroupLayers(layer, output)
          continue
        }

                output.push(layer)
            }
        output.push(layer)
      }

            return output
        },
      return output
    },

        /**
    /**
         * Implements the singleMarkerMode option.
         * @param layer Marker to re-style using the Clusters iconCreateFunction.
         * @returns {L.Icon} The newly created icon.
         * @private
         */
        _overrideMarkerIcon: function(layer) {
            var icon = layer.options.icon = this.options.iconCreateFunction({
                getChildCount: function() {
                    return 1
                },
                getAllChildMarkers: function() {
                    return [layer]
                }
    _overrideMarkerIcon: function (layer) {
      var icon = layer.options.icon = this.options.iconCreateFunction({
        getChildCount: function () {
          return 1
        },
        getAllChildMarkers: function () {
          return [layer]
        }
      })

      return icon
    }
  })

  //  Constant bounds used in case option "removeOutsideVisibleBounds" is set to false.
  L.MarkerClusterGroup.include({
    _mapBoundsInfinite: new L.LatLngBounds(new L.LatLng(-Infinity, -Infinity), new L.LatLng(Infinity, Infinity))
  })

  L.MarkerClusterGroup.include({
    _noAnimation: {
      // Non Animated versions of everything
      _animationStart: function () {
        // Do nothing...
      },
      _animationZoomIn: function (previousZoomLevel, newZoomLevel) {
        this._topClusterLevel._recursivelyRemoveChildrenFromMap(this._currentShownBounds, Math.floor(this._map.getMinZoom()), previousZoomLevel)
        this._topClusterLevel._recursivelyAddChildrenToMap(null, newZoomLevel, this._getExpandedVisibleBounds())

        // We didn't actually animate, but we use this event to mean "clustering animations have finished"
        this.fire('animationend')
      },
      _animationZoomOut: function (previousZoomLevel, newZoomLevel) {
        this._topClusterLevel._recursivelyRemoveChildrenFromMap(this._currentShownBounds, Math.floor(this._map.getMinZoom()), previousZoomLevel)
        this._topClusterLevel._recursivelyAddChildrenToMap(null, newZoomLevel, this._getExpandedVisibleBounds())

        // We didn't actually animate, but we use this event to mean "clustering animations have finished"
        this.fire('animationend')
      },
      _animationAddLayer: function (layer, newCluster) {
        this._animationAddLayerNonAnimated(layer, newCluster)
      }
    },

    _withAnimation: {
      // Animated versions here
      _animationStart: function () {
        this._map._mapPane.className += ' leaflet-cluster-anim'
        this._inZoomAnimation++
      },

      _animationZoomIn: function (previousZoomLevel, newZoomLevel) {
        var bounds = this._getExpandedVisibleBounds()
        var fg = this._featureGroup
        var minZoom = Math.floor(this._map.getMinZoom())
        var i

        this._ignoreMove = true

        // Add all children of current clusters to map and remove those clusters from map
        this._topClusterLevel._recursively(bounds, previousZoomLevel, minZoom, function (c) {
          var startPos = c._latlng
          var markers = c._markers
          var m

          if (!bounds.contains(startPos)) {
            startPos = null
          }

          if (c._isSingleParent() && previousZoomLevel + 1 === newZoomLevel) { // Immediately add the new child and remove us
            fg.removeLayer(c)
            c._recursivelyAddChildrenToMap(null, newZoomLevel, bounds)
          } else {
            // Fade out old cluster
            c.clusterHide()
            c._recursivelyAddChildrenToMap(startPos, newZoomLevel, bounds)
          }

          // Remove all markers that aren't visible any more
          // TODO: Do we actually need to do this on the higher levels too?
          for (i = markers.length - 1; i >= 0; i--) {
            m = markers[i]
            if (!bounds.contains(m._latlng)) {
              fg.removeLayer(m)
            }
          }
        })

        this._forceLayout()

        // Update opacities
        this._topClusterLevel._recursivelyBecomeVisible(bounds, newZoomLevel)
        // TODO Maybe? Update markers in _recursivelyBecomeVisible
        fg.eachLayer(function (n) {
          if (!(n instanceof L.MarkerCluster) && n._icon) {
            n.clusterShow()
          }
        })

        // update the positions of the just added clusters/markers
        this._topClusterLevel._recursively(bounds, previousZoomLevel, newZoomLevel, function (c) {
          c._recursivelyRestoreChildPositions(newZoomLevel)
        })

        this._ignoreMove = false

        // Remove the old clusters and close the zoom animation
        this._enqueue(function () {
          // update the positions of the just added clusters/markers
          this._topClusterLevel._recursively(bounds, previousZoomLevel, minZoom, function (c) {
            fg.removeLayer(c)
            c.clusterShow()
          })

          this._animationEnd()
        })
      },

      _animationZoomOut: function (previousZoomLevel, newZoomLevel) {
        this._animationZoomOutSingle(this._topClusterLevel, previousZoomLevel - 1, newZoomLevel)

        // Need to add markers for those that weren't on the map before but are now
        this._topClusterLevel._recursivelyAddChildrenToMap(null, newZoomLevel, this._getExpandedVisibleBounds())
        // Remove markers that were on the map before but won't be now
        this._topClusterLevel._recursivelyRemoveChildrenFromMap(this._currentShownBounds, Math.floor(this._map.getMinZoom()), previousZoomLevel, this._getExpandedVisibleBounds())
      },

      _animationAddLayer: function (layer, newCluster) {
        var me = this
        var fg = this._featureGroup

        fg.addLayer(layer)
        if (newCluster !== layer) {
          if (newCluster._childCount > 2) { // Was already a cluster
            newCluster._updateIcon()
            this._forceLayout()
            this._animationStart()

            layer._setPos(this._map.latLngToLayerPoint(newCluster.getLatLng()))
            layer.clusterHide()

            this._enqueue(function () {
              fg.removeLayer(layer)
              layer.clusterShow()

              me._animationEnd()
            })
          } else { // Just became a cluster
            this._forceLayout()

            return icon
            me._animationStart()
            me._animationZoomOutSingle(newCluster, this._map.getMaxZoom(), this._zoom)
          }
        }
    })
      }
    },

//  Constant bounds used in case option "removeOutsideVisibleBounds" is set to false.
    L.MarkerClusterGroup.include({
        _mapBoundsInfinite: new L.LatLngBounds(new L.LatLng(-Infinity, -Infinity), new L.LatLng(Infinity, Infinity))
    })
    //  Private methods for animated versions.
    _animationZoomOutSingle: function (cluster, previousZoomLevel, newZoomLevel) {
      var bounds = this._getExpandedVisibleBounds()
      var minZoom = Math.floor(this._map.getMinZoom())

    L.MarkerClusterGroup.include({
        _noAnimation: {
            // Non Animated versions of everything
            _animationStart: function() {
                // Do nothing...
            },
            _animationZoomIn: function(previousZoomLevel, newZoomLevel) {
                this._topClusterLevel._recursivelyRemoveChildrenFromMap(this._currentShownBounds, Math.floor(this._map.getMinZoom()), previousZoomLevel);
                this._topClusterLevel._recursivelyAddChildrenToMap(null, newZoomLevel, this._getExpandedVisibleBounds())
      // Animate all of the markers in the clusters to move to their cluster center point
      cluster._recursivelyAnimateChildrenInAndAddSelfToMap(bounds, minZoom, previousZoomLevel + 1, newZoomLevel)

                // We didn't actually animate, but we use this event to mean "clustering animations have finished"
                this.fire('animationend')
            },
            _animationZoomOut: function(previousZoomLevel, newZoomLevel) {
                this._topClusterLevel._recursivelyRemoveChildrenFromMap(this._currentShownBounds, Math.floor(this._map.getMinZoom()), previousZoomLevel);
                this._topClusterLevel._recursivelyAddChildrenToMap(null, newZoomLevel, this._getExpandedVisibleBounds())
      var me = this

                // We didn't actually animate, but we use this event to mean "clustering animations have finished"
                this.fire('animationend')
            },
            _animationAddLayer: function(layer, newCluster) {
                this._animationAddLayerNonAnimated(layer, newCluster)
            }
        },
      // Update the opacity (If we immediately set it they won't animate)
      this._forceLayout()
      cluster._recursivelyBecomeVisible(bounds, newZoomLevel)

        _withAnimation: {
            // Animated versions here
            _animationStart: function() {
                this._map._mapPane.className += ' leaflet-cluster-anim'
                this._inZoomAnimation++
            },

            _animationZoomIn: function(previousZoomLevel, newZoomLevel) {
                var bounds = this._getExpandedVisibleBounds(),
                    fg = this._featureGroup,
                    minZoom = Math.floor(this._map.getMinZoom()),
                    i

                this._ignoreMove = true

                // Add all children of current clusters to map and remove those clusters from map
                this._topClusterLevel._recursively(bounds, previousZoomLevel, minZoom, function(c) {
                    var startPos = c._latlng,
                        markers = c._markers,
                        m

                    if (!bounds.contains(startPos)) {
                        startPos = null
                    }

                    if (c._isSingleParent() && previousZoomLevel + 1 === newZoomLevel) { // Immediately add the new child and remove us
                        fg.removeLayer(c)
                        c._recursivelyAddChildrenToMap(null, newZoomLevel, bounds)
                    } else {
                        // Fade out old cluster
                        c.clusterHide()
                        c._recursivelyAddChildrenToMap(startPos, newZoomLevel, bounds)
                    }

                    // Remove all markers that aren't visible any more
                    // TODO: Do we actually need to do this on the higher levels too?
                    for (i = markers.length - 1; i >= 0; i--) {
                        m = markers[i]
                        if (!bounds.contains(m._latlng)) {
                            fg.removeLayer(m)
                        }
                    }

                });

                this._forceLayout()

                // Update opacities
                this._topClusterLevel._recursivelyBecomeVisible(bounds, newZoomLevel);
                // TODO Maybe? Update markers in _recursivelyBecomeVisible
                fg.eachLayer(function(n) {
                    if (!(n instanceof L.MarkerCluster) && n._icon) {
                        n.clusterShow()
                    }
                });

                // update the positions of the just added clusters/markers
                this._topClusterLevel._recursively(bounds, previousZoomLevel, newZoomLevel, function(c) {
                    c._recursivelyRestoreChildPositions(newZoomLevel);
                });

                this._ignoreMove = false;

                // Remove the old clusters and close the zoom animation
                this._enqueue(function() {
                    // update the positions of the just added clusters/markers
                    this._topClusterLevel._recursively(bounds, previousZoomLevel, minZoom, function(c) {
                        fg.removeLayer(c)
                        c.clusterShow()
                    })

                    this._animationEnd()
                })
            },

            _animationZoomOut: function(previousZoomLevel, newZoomLevel) {
                this._animationZoomOutSingle(this._topClusterLevel, previousZoomLevel - 1, newZoomLevel)

                // Need to add markers for those that weren't on the map before but are now
                this._topClusterLevel._recursivelyAddChildrenToMap(null, newZoomLevel, this._getExpandedVisibleBounds())
                // Remove markers that were on the map before but won't be now
                this._topClusterLevel._recursivelyRemoveChildrenFromMap(this._currentShownBounds, Math.floor(this._map.getMinZoom()), previousZoomLevel, this._getExpandedVisibleBounds());
            },

            _animationAddLayer: function(layer, newCluster) {
                var me = this,
                    fg = this._featureGroup

                fg.addLayer(layer)
                if (newCluster !== layer) {
                    if (newCluster._childCount > 2) { // Was already a cluster
                        newCluster._updateIcon()
                        this._forceLayout()
                        this._animationStart()

                        layer._setPos(this._map.latLngToLayerPoint(newCluster.getLatLng()))
                        layer.clusterHide()

                        this._enqueue(function() {
                            fg.removeLayer(layer)
                            layer.clusterShow()

                            me._animationEnd()
                        });

                    } else { // Just became a cluster
                        this._forceLayout()

                        me._animationStart()
                        me._animationZoomOutSingle(newCluster, this._map.getMaxZoom(), this._zoom)
                    }
                }
            }
        },

        //  Private methods for animated versions.
        _animationZoomOutSingle: function(cluster, previousZoomLevel, newZoomLevel) {
            var bounds = this._getExpandedVisibleBounds(),
                minZoom = Math.floor(this._map.getMinZoom())

            // Animate all of the markers in the clusters to move to their cluster center point
            cluster._recursivelyAnimateChildrenInAndAddSelfToMap(bounds, minZoom, previousZoomLevel + 1, newZoomLevel)

            var me = this

            // Update the opacity (If we immediately set it they won't animate)
            this._forceLayout();
            cluster._recursivelyBecomeVisible(bounds, newZoomLevel)

            // TODO: Maybe use the transition timing stuff to make this more reliable
            // When the animations are done, tidy up
            this._enqueue(function() {
                // This cluster stopped being a cluster before the timeout fired
                if (cluster._childCount === 1) {
                    var m = cluster._markers[0]
                    // If we were in a cluster animation at the time then the opacity and position of our child could be wrong now, so fix it
                    this._ignoreMove = true
                    m.setLatLng(m.getLatLng())
                    this._ignoreMove = false
                    if (m.clusterShow) {
                        m.clusterShow()
                    }
                } else {
                    cluster._recursively(bounds, newZoomLevel, minZoom, function(c) {
                        c._recursivelyRemoveChildrenFromMap(bounds, minZoom, previousZoomLevel + 1)
                    })
                }
                me._animationEnd()
            });
        },

        _animationEnd: function() {
            if (this._map) {
                this._map._mapPane.className = this._map._mapPane.className.replace(' leaflet-cluster-anim', '');
            }
            this._inZoomAnimation--
            this.fire('animationend')
        },

        // Force a browser layout of stuff in the map
        //  Should apply the current opacity and location to all elements so we can update them again for an animation
        _forceLayout: function() {
            // In my testing this works, infact offsetWidth of any element seems to work.
            // Could loop all this._layers and do this for each _icon if it stops working

            L.Util.falseFn(document.body.offsetWidth)
      // TODO: Maybe use the transition timing stuff to make this more reliable
      // When the animations are done, tidy up
      this._enqueue(function () {
        // This cluster stopped being a cluster before the timeout fired
        if (cluster._childCount === 1) {
          var m = cluster._markers[0]
          // If we were in a cluster animation at the time then the opacity and position of our child could be wrong now, so fix it
          this._ignoreMove = true
          m.setLatLng(m.getLatLng())
          this._ignoreMove = false
          if (m.clusterShow) {
            m.clusterShow()
          }
        } else {
          cluster._recursively(bounds, newZoomLevel, minZoom, function (c) {
            c._recursivelyRemoveChildrenFromMap(bounds, minZoom, previousZoomLevel + 1)
          })
        }
    });
        me._animationEnd()
      })
    },

    L.markerClusterGroup = function(options) {
        return new L.MarkerClusterGroup(options)
    };
    _animationEnd: function () {
      if (this._map) {
        this._map._mapPane.className = this._map._mapPane.className.replace(' leaflet-cluster-anim', '')
      }
      this._inZoomAnimation--
      this.fire('animationend')
    },

    var MarkerCluster = L.MarkerCluster = L.Marker.extend({
        options: L.Icon.prototype.options,
    // Force a browser layout of stuff in the map
    //  Should apply the current opacity and location to all elements so we can update them again for an animation
    _forceLayout: function () {
      // In my testing this works, infact offsetWidth of any element seems to work.
      // Could loop all this._layers and do this for each _icon if it stops working

        initialize: function(group, zoom, a, b) {
            L.Marker.prototype.initialize.call(this, a ? (a._cLatLng || a.getLatLng()) : new L.LatLng(0, 0),
                { icon: this, pane: group.options.clusterPane })
      L.Util.falseFn(document.body.offsetWidth)
    }
  })

            this._group = group
            this._zoom = zoom
  L.markerClusterGroup = function (options) {
    return new L.MarkerClusterGroup(options)
  }

            this._markers = []
            this._childClusters = []
            this._childCount = 0
            this._iconNeedsUpdate = true
            this._boundsNeedUpdate = true
  var MarkerCluster = L.MarkerCluster = L.Marker.extend({
    options: L.Icon.prototype.options,

            this._bounds = new L.LatLngBounds()
    initialize: function (group, zoom, a, b) {
      L.Marker.prototype.initialize.call(this, a ? (a._cLatLng || a.getLatLng()) : new L.LatLng(0, 0),
        { icon: this, pane: group.options.clusterPane })

            if (a) {
                this._addChild(a);
            }
            if (b) {
                this._addChild(b);
            }
        },
      this._group = group
      this._zoom = zoom

        // Recursively retrieve all child markers of this cluster
        getAllChildMarkers: function(storageArray, ignoreDraggedMarker) {
            storageArray = storageArray || []
      this._markers = []
      this._childClusters = []
      this._childCount = 0
      this._iconNeedsUpdate = true
      this._boundsNeedUpdate = true

            for (var i = this._childClusters.length - 1; i >= 0; i--) {
                this._childClusters[i].getAllChildMarkers(storageArray)
            }
      this._bounds = new L.LatLngBounds()

            for (var j = this._markers.length - 1; j >= 0; j--) {
                if (ignoreDraggedMarker && this._markers[j].__dragStart) {
                    continue
                }
                storageArray.push(this._markers[j])
            }
      if (a) {
        this._addChild(a)
      }
      if (b) {
        this._addChild(b)
      }
    },

            return storageArray
        },
    // Recursively retrieve all child markers of this cluster
    getAllChildMarkers: function (storageArray, ignoreDraggedMarker) {
      storageArray = storageArray || []

        // Returns the count of how many child markers we have
        getChildCount: function() {
            return this._childCount;
        },
      for (var i = this._childClusters.length - 1; i >= 0; i--) {
        this._childClusters[i].getAllChildMarkers(storageArray)
      }

        // Zoom to the minimum of showing all of the child markers, or the extents of this cluster
        zoomToBounds: function(fitBoundsOptions) {
            var childClusters = this._childClusters.slice(),
                map = this._group._map,
                boundsZoom = map.getBoundsZoom(this._bounds),
                zoom = this._zoom + 1,
                mapZoom = map.getZoom(),
                i;
      for (var j = this._markers.length - 1; j >= 0; j--) {
        if (ignoreDraggedMarker && this._markers[j].__dragStart) {
          continue
        }
        storageArray.push(this._markers[j])
      }

            // calculate how far we need to zoom down to see all of the markers
            while (childClusters.length > 0 && boundsZoom > zoom) {
                zoom++;
                var newClusters = [];
                for (i = 0; i < childClusters.length; i++) {
                    newClusters = newClusters.concat(childClusters[i]._childClusters);
                }
                childClusters = newClusters;
            }
      return storageArray
    },

            if (boundsZoom > zoom) {
                this._group._map.setView(this._latlng, zoom);
            } else if (boundsZoom <= mapZoom) { // If fitBounds wouldn't zoom us down, zoom us down instead
                this._group._map.setView(this._latlng, mapZoom + 1);
            } else {
                this._group._map.fitBounds(this._bounds, fitBoundsOptions)
            }
        },
    // Returns the count of how many child markers we have
    getChildCount: function () {
      return this._childCount
    },

        getBounds: function() {
            var bounds = new L.LatLngBounds()
            bounds.extend(this._bounds)
            return bounds
        },
    // Zoom to the minimum of showing all of the child markers, or the extents of this cluster
    zoomToBounds: function (fitBoundsOptions) {
      var childClusters = this._childClusters.slice()
      var map = this._group._map
      var boundsZoom = map.getBoundsZoom(this._bounds)
      var zoom = this._zoom + 1
      var mapZoom = map.getZoom()
      var i

        _updateIcon: function() {
            this._iconNeedsUpdate = true
            if (this._icon) {
                this.setIcon(this)
            }
        },
      // calculate how far we need to zoom down to see all of the markers
      while (childClusters.length > 0 && boundsZoom > zoom) {
        zoom++
        var newClusters = []
        for (i = 0; i < childClusters.length; i++) {
          newClusters = newClusters.concat(childClusters[i]._childClusters)
        }
        childClusters = newClusters
      }

        //  Cludge for Icon, we pretend to be an icon for performance
        createIcon: function() {
            if (this._iconNeedsUpdate) {
                this._iconObj = this._group.options.iconCreateFunction(this);
                this._iconNeedsUpdate = false
            }
            return this._iconObj.createIcon()
        },
        createShadow: function() {
            return this._iconObj.createShadow()
        },
      if (boundsZoom > zoom) {
        this._group._map.setView(this._latlng, zoom)
      } else if (boundsZoom <= mapZoom) { // If fitBounds wouldn't zoom us down, zoom us down instead
        this._group._map.setView(this._latlng, mapZoom + 1)
      } else {
        this._group._map.fitBounds(this._bounds, fitBoundsOptions)
      }
    },

        _addChild: function(new1, isNotificationFromChild) {
            this._iconNeedsUpdate = true
    getBounds: function () {
      var bounds = new L.LatLngBounds()
      bounds.extend(this._bounds)
      return bounds
    },

            this._boundsNeedUpdate = true
            this._setClusterCenter(new1)
    _updateIcon: function () {
      this._iconNeedsUpdate = true
      if (this._icon) {
        this.setIcon(this)
      }
    },

            if (new1 instanceof L.MarkerCluster) {
                if (!isNotificationFromChild) {
                    this._childClusters.push(new1)
                    new1.__parent = this
                }
                this._childCount += new1._childCount
            } else {
                if (!isNotificationFromChild) {
                    this._markers.push(new1)
                }
                this._childCount++
            }
    //  Cludge for Icon, we pretend to be an icon for performance
    createIcon: function () {
      if (this._iconNeedsUpdate) {
        this._iconObj = this._group.options.iconCreateFunction(this)
        this._iconNeedsUpdate = false
      }
      return this._iconObj.createIcon()
    },
    createShadow: function () {
      return this._iconObj.createShadow()
    },

            if (this.__parent) {
                this.__parent._addChild(new1, true)
            }
        },
    _addChild: function (new1, isNotificationFromChild) {
      this._iconNeedsUpdate = true

        /**
      this._boundsNeedUpdate = true
      this._setClusterCenter(new1)

      if (new1 instanceof L.MarkerCluster) {
        if (!isNotificationFromChild) {
          this._childClusters.push(new1)
          new1.__parent = this
        }
        this._childCount += new1._childCount
      } else {
        if (!isNotificationFromChild) {
          this._markers.push(new1)
        }
        this._childCount++
      }

      if (this.__parent) {
        this.__parent._addChild(new1, true)
      }
    },

    /**
         * Makes sure the cluster center is set. If not, uses the child center if it is a cluster, or the marker position.
         * @param child L.MarkerCluster|L.Marker that will be used as cluster center if not defined yet.
         * @private
         */
        _setClusterCenter: function(child) {
            if (!this._cLatLng) {
                //  when clustering, take position of the first point as the cluster center
                this._cLatLng = child._cLatLng || child._latlng
            }
        },
    _setClusterCenter: function (child) {
      if (!this._cLatLng) {
        //  when clustering, take position of the first point as the cluster center
        this._cLatLng = child._cLatLng || child._latlng
      }
    },

        /**
    /**
         * Assigns impossible bounding values so that the next extend entirely determines the new bounds.
         * This method avoids having to trash the previous L.LatLngBounds object and to create a new one, which is much slower for this class.
         * As long as the bounds are not extended, most other methods would probably fail, as they would with bounds initialized but not extended.
         * @private
         */
        _resetBounds: function() {
            var bounds = this._bounds
    _resetBounds: function () {
      var bounds = this._bounds

            if (bounds._southWest) {
                bounds._southWest.lat = Infinity
                bounds._southWest.lng = Infinity
            }
            if (bounds._northEast) {
                bounds._northEast.lat = -Infinity
                bounds._northEast.lng = -Infinity
            }
        },
      if (bounds._southWest) {
        bounds._southWest.lat = Infinity
        bounds._southWest.lng = Infinity
      }
      if (bounds._northEast) {
        bounds._northEast.lat = -Infinity
        bounds._northEast.lng = -Infinity
      }
    },

        _recalculateBounds: function() {
            var markers = this._markers,
                childClusters = this._childClusters,
                latSum = 0,
                lngSum = 0,
                totalCount = this._childCount,
                i, child, childLatLng, childCount
    _recalculateBounds: function () {
      var markers = this._markers
      var childClusters = this._childClusters
      var latSum = 0
      var lngSum = 0
      var totalCount = this._childCount
      var i; var child; var childLatLng; var childCount

            //  Case where all markers are removed from the map and we are left with just an empty _topClusterLevel.
            if (totalCount === 0) {
                return
            }
      //  Case where all markers are removed from the map and we are left with just an empty _topClusterLevel.
      if (totalCount === 0) {
        return
      }

            //  Reset rather than creating a new object, for performance.
            this._resetBounds()
      //  Reset rather than creating a new object, for performance.
      this._resetBounds()

            //  Child markers.
            for (i = 0; i < markers.length; i++) {
                childLatLng = markers[i]._latlng
      //  Child markers.
      for (i = 0; i < markers.length; i++) {
        childLatLng = markers[i]._latlng

                this._bounds.extend(childLatLng)
        this._bounds.extend(childLatLng)

                latSum += childLatLng.lat
                lngSum += childLatLng.lng
            }
        latSum += childLatLng.lat
        lngSum += childLatLng.lng
      }

            //  Child clusters.
            for (i = 0; i < childClusters.length; i++) {
                child = childClusters[i]
      //  Child clusters.
      for (i = 0; i < childClusters.length; i++) {
        child = childClusters[i]

                //  Re-compute child bounds and weighted position first if necessary.
                if (child._boundsNeedUpdate) {
                    child._recalculateBounds()
                }

                this._bounds.extend(child._bounds)

                childLatLng = child._wLatLng
                childCount = child._childCount

                latSum += childLatLng.lat * childCount
                lngSum += childLatLng.lng * childCount
            }

            this._latlng = this._wLatLng = new L.LatLng(latSum / totalCount, lngSum / totalCount)

            //  Reset dirty flag.
            this._boundsNeedUpdate = false
        },

        //  Set our markers position as given and add it to the map
        _addToMap: function(startPos) {
            if (startPos) {
                this._backupLatlng = this._latlng
                this.setLatLng(startPos)
            }
            this._group._featureGroup.addLayer(this)
        },

        _recursivelyAnimateChildrenIn: function(bounds, center, maxZoom) {
            this._recursively(bounds, this._group._map.getMinZoom(), maxZoom - 1,
                function(c) {
                    var markers = c._markers,
                        i, m
                    for (i = markers.length - 1; i >= 0; i--) {
                        m = markers[i]

                        //  Only do it if the icon is still on the map
                        if (m._icon) {
                            m._setPos(center)
                            m.clusterHide()
                        }
                    }
                },
                function(c) {
                    var childClusters = c._childClusters,
                        j, cm
                    for (j = childClusters.length - 1; j >= 0; j--) {
                        cm = childClusters[j]
                        if (cm._icon) {
                            cm._setPos(center)
                            cm.clusterHide()
                        }
                    }
                }
            );
        },

        _recursivelyAnimateChildrenInAndAddSelfToMap: function(bounds, mapMinZoom, previousZoomLevel, newZoomLevel) {
            this._recursively(bounds, newZoomLevel, mapMinZoom,
                function(c) {
                    c._recursivelyAnimateChildrenIn(bounds, c._group._map.latLngToLayerPoint(c.getLatLng()).round(), previousZoomLevel);

                    //  TODO: depthToAnimateIn affects _isSingleParent, if there is a multizoom we may/may not be.
                    //  As a hack we only do a animation free zoom on a single level zoom, if someone does multiple levels then we always animate
                    if (c._isSingleParent() && previousZoomLevel - 1 === newZoomLevel) {
                        c.clusterShow()
                        c._recursivelyRemoveChildrenFromMap(bounds, mapMinZoom, previousZoomLevel) //  Immediately remove our children as we are replacing them. TODO previousBounds not bounds
                    } else {
                        c.clusterHide()
                    }

                    c._addToMap()
                }
            )
        },

        _recursivelyBecomeVisible: function(bounds, zoomLevel) {
            this._recursively(bounds, this._group._map.getMinZoom(), zoomLevel, null, function(c) {
                c.clusterShow()
            })
        },

        _recursivelyAddChildrenToMap: function(startPos, zoomLevel, bounds) {
            this._recursively(bounds, this._group._map.getMinZoom() - 1, zoomLevel,
                function(c) {
                    if (zoomLevel === c._zoom) {
                        return
                    }

                    //  Add our child markers at startPos (so they can be animated out)
                    for (var i = c._markers.length - 1; i >= 0; i--) {
                        var nm = c._markers[i]

                        if (!bounds.contains(nm._latlng)) {
                            continue
                        }

                        if (startPos) {
                            nm._backupLatlng = nm.getLatLng()

                            nm.setLatLng(startPos)
                            if (nm.clusterHide) {
                                nm.clusterHide()
                            }
                        }

                        c._group._featureGroup.addLayer(nm)
                    }
                },
                function(c) {
                    c._addToMap(startPos)
                }
            )
        },

        _recursivelyRestoreChildPositions: function(zoomLevel) {
            //  Fix positions of child markers
            for (var i = this._markers.length - 1; i >= 0; i--) {
                var nm = this._markers[i]
                if (nm._backupLatlng) {
                    nm.setLatLng(nm._backupLatlng)
                    delete nm._backupLatlng
                }
            }

            if (zoomLevel - 1 === this._zoom) {
                //  Reposition child clusters
                for (var j = this._childClusters.length - 1; j >= 0; j--) {
                    this._childClusters[j]._restorePosition();
                }
            } else {
                for (var k = this._childClusters.length - 1; k >= 0; k--) {
                    this._childClusters[k]._recursivelyRestoreChildPositions(zoomLevel)
                }
            }
        },

        _restorePosition: function() {
            if (this._backupLatlng) {
                this.setLatLng(this._backupLatlng)
                delete this._backupLatlng
            }
        },

        //  exceptBounds: If set, don't remove any markers/clusters in it
        _recursivelyRemoveChildrenFromMap: function(previousBounds, mapMinZoom, zoomLevel, exceptBounds) {
            var m, i
            this._recursively(previousBounds, mapMinZoom - 1, zoomLevel - 1,
                function(c) {
                    //  Remove markers at every level
                    for (i = c._markers.length - 1; i >= 0; i--) {
                        m = c._markers[i]
                        if (!exceptBounds || !exceptBounds.contains(m._latlng)) {
                            c._group._featureGroup.removeLayer(m)
                            if (m.clusterShow) {
                                m.clusterShow()
                            }
                        }
                    }
                },
                function(c) {
                    //  Remove child clusters at just the bottom level
                    for (i = c._childClusters.length - 1; i >= 0; i--) {
                        m = c._childClusters[i]
                        if (!exceptBounds || !exceptBounds.contains(m._latlng)) {
                            c._group._featureGroup.removeLayer(m)
                            if (m.clusterShow) {
                                m.clusterShow()
                            }
                        }
                    }
                }
            )
        },

        //  Run the given functions recursively to this and child clusters
        //  boundsToApplyTo: a L.LatLngBounds representing the bounds of what clusters to recurse in to
        //  zoomLevelToStart: zoom level to start running functions (inclusive)
        //  zoomLevelToStop: zoom level to stop running functions (inclusive)
        //  runAtEveryLevel: function that takes an L.MarkerCluster as an argument that should be applied on every level
        //  runAtBottomLevel: function that takes an L.MarkerCluster as an argument that should be applied at only the bottom level
        _recursively: function(boundsToApplyTo, zoomLevelToStart, zoomLevelToStop, runAtEveryLevel, runAtBottomLevel) {
            var childClusters = this._childClusters,
                zoom = this._zoom,
                i, c

            if (zoomLevelToStart <= zoom) {
                if (runAtEveryLevel) {
                    runAtEveryLevel(this)
                }
                if (runAtBottomLevel && zoom === zoomLevelToStop) {
                    runAtBottomLevel(this)
                }
            }

            if (zoom < zoomLevelToStart || zoom < zoomLevelToStop) {
                for (i = childClusters.length - 1; i >= 0; i--) {
                    c = childClusters[i]
                    if (c._boundsNeedUpdate) {
                        c._recalculateBounds()
                    }
                    if (boundsToApplyTo.intersects(c._bounds)) {
                        c._recursively(boundsToApplyTo, zoomLevelToStart, zoomLevelToStop, runAtEveryLevel, runAtBottomLevel)
                    }
                }
            }
        },

        //  Returns true if we are the parent of only one cluster and that cluster is the same as us
        _isSingleParent: function() {
            //  Don't need to check this._markers as the rest won't work if there are any
            return this._childClusters.length > 0 && this._childClusters[0]._childCount === this._childCount
        //  Re-compute child bounds and weighted position first if necessary.
        if (child._boundsNeedUpdate) {
          child._recalculateBounds()
        }
    });

    /*
        this._bounds.extend(child._bounds)

        childLatLng = child._wLatLng
        childCount = child._childCount

        latSum += childLatLng.lat * childCount
        lngSum += childLatLng.lng * childCount
      }

      this._latlng = this._wLatLng = new L.LatLng(latSum / totalCount, lngSum / totalCount)

      //  Reset dirty flag.
      this._boundsNeedUpdate = false
    },

    //  Set our markers position as given and add it to the map
    _addToMap: function (startPos) {
      if (startPos) {
        this._backupLatlng = this._latlng
        this.setLatLng(startPos)
      }
      this._group._featureGroup.addLayer(this)
    },

    _recursivelyAnimateChildrenIn: function (bounds, center, maxZoom) {
      this._recursively(bounds, this._group._map.getMinZoom(), maxZoom - 1,
        function (c) {
          var markers = c._markers
          var i; var m
          for (i = markers.length - 1; i >= 0; i--) {
            m = markers[i]

            //  Only do it if the icon is still on the map
            if (m._icon) {
              m._setPos(center)
              m.clusterHide()
            }
          }
        },
        function (c) {
          var childClusters = c._childClusters
          var j; var cm
          for (j = childClusters.length - 1; j >= 0; j--) {
            cm = childClusters[j]
            if (cm._icon) {
              cm._setPos(center)
              cm.clusterHide()
            }
          }
        }
      )
    },

    _recursivelyAnimateChildrenInAndAddSelfToMap: function (bounds, mapMinZoom, previousZoomLevel, newZoomLevel) {
      this._recursively(bounds, newZoomLevel, mapMinZoom,
        function (c) {
          c._recursivelyAnimateChildrenIn(bounds, c._group._map.latLngToLayerPoint(c.getLatLng()).round(), previousZoomLevel)

          //  TODO: depthToAnimateIn affects _isSingleParent, if there is a multizoom we may/may not be.
          //  As a hack we only do a animation free zoom on a single level zoom, if someone does multiple levels then we always animate
          if (c._isSingleParent() && previousZoomLevel - 1 === newZoomLevel) {
            c.clusterShow()
            c._recursivelyRemoveChildrenFromMap(bounds, mapMinZoom, previousZoomLevel) //  Immediately remove our children as we are replacing them. TODO previousBounds not bounds
          } else {
            c.clusterHide()
          }

          c._addToMap()
        }
      )
    },

    _recursivelyBecomeVisible: function (bounds, zoomLevel) {
      this._recursively(bounds, this._group._map.getMinZoom(), zoomLevel, null, function (c) {
        c.clusterShow()
      })
    },

    _recursivelyAddChildrenToMap: function (startPos, zoomLevel, bounds) {
      this._recursively(bounds, this._group._map.getMinZoom() - 1, zoomLevel,
        function (c) {
          if (zoomLevel === c._zoom) {
            return
          }

          //  Add our child markers at startPos (so they can be animated out)
          for (var i = c._markers.length - 1; i >= 0; i--) {
            var nm = c._markers[i]

            if (!bounds.contains(nm._latlng)) {
              continue
            }

            if (startPos) {
              nm._backupLatlng = nm.getLatLng()

              nm.setLatLng(startPos)
              if (nm.clusterHide) {
                nm.clusterHide()
              }
            }

            c._group._featureGroup.addLayer(nm)
          }
        },
        function (c) {
          c._addToMap(startPos)
        }
      )
    },

    _recursivelyRestoreChildPositions: function (zoomLevel) {
      //  Fix positions of child markers
      for (var i = this._markers.length - 1; i >= 0; i--) {
        var nm = this._markers[i]
        if (nm._backupLatlng) {
          nm.setLatLng(nm._backupLatlng)
          delete nm._backupLatlng
        }
      }

      if (zoomLevel - 1 === this._zoom) {
        //  Reposition child clusters
        for (var j = this._childClusters.length - 1; j >= 0; j--) {
          this._childClusters[j]._restorePosition()
        }
      } else {
        for (var k = this._childClusters.length - 1; k >= 0; k--) {
          this._childClusters[k]._recursivelyRestoreChildPositions(zoomLevel)
        }
      }
    },

    _restorePosition: function () {
      if (this._backupLatlng) {
        this.setLatLng(this._backupLatlng)
        delete this._backupLatlng
      }
    },

    //  exceptBounds: If set, don't remove any markers/clusters in it
    _recursivelyRemoveChildrenFromMap: function (previousBounds, mapMinZoom, zoomLevel, exceptBounds) {
      var m, i
      this._recursively(previousBounds, mapMinZoom - 1, zoomLevel - 1,
        function (c) {
          //  Remove markers at every level
          for (i = c._markers.length - 1; i >= 0; i--) {
            m = c._markers[i]
            if (!exceptBounds || !exceptBounds.contains(m._latlng)) {
              c._group._featureGroup.removeLayer(m)
              if (m.clusterShow) {
                m.clusterShow()
              }
            }
          }
        },
        function (c) {
          //  Remove child clusters at just the bottom level
          for (i = c._childClusters.length - 1; i >= 0; i--) {
            m = c._childClusters[i]
            if (!exceptBounds || !exceptBounds.contains(m._latlng)) {
              c._group._featureGroup.removeLayer(m)
              if (m.clusterShow) {
                m.clusterShow()
              }
            }
          }
        }
      )
    },

    //  Run the given functions recursively to this and child clusters
    //  boundsToApplyTo: a L.LatLngBounds representing the bounds of what clusters to recurse in to
    //  zoomLevelToStart: zoom level to start running functions (inclusive)
    //  zoomLevelToStop: zoom level to stop running functions (inclusive)
    //  runAtEveryLevel: function that takes an L.MarkerCluster as an argument that should be applied on every level
    //  runAtBottomLevel: function that takes an L.MarkerCluster as an argument that should be applied at only the bottom level
    _recursively: function (boundsToApplyTo, zoomLevelToStart, zoomLevelToStop, runAtEveryLevel, runAtBottomLevel) {
      var childClusters = this._childClusters
      var zoom = this._zoom
      var i; var c

      if (zoomLevelToStart <= zoom) {
        if (runAtEveryLevel) {
          runAtEveryLevel(this)
        }
        if (runAtBottomLevel && zoom === zoomLevelToStop) {
          runAtBottomLevel(this)
        }
      }

      if (zoom < zoomLevelToStart || zoom < zoomLevelToStop) {
        for (i = childClusters.length - 1; i >= 0; i--) {
          c = childClusters[i]
          if (c._boundsNeedUpdate) {
            c._recalculateBounds()
          }
          if (boundsToApplyTo.intersects(c._bounds)) {
            c._recursively(boundsToApplyTo, zoomLevelToStart, zoomLevelToStop, runAtEveryLevel, runAtBottomLevel)
          }
        }
      }
    },

    //  Returns true if we are the parent of only one cluster and that cluster is the same as us
    _isSingleParent: function () {
      //  Don't need to check this._markers as the rest won't work if there are any
      return this._childClusters.length > 0 && this._childClusters[0]._childCount === this._childCount
    }
  })

  /*
    * Extends L.Marker to include two extra methods: clusterHide and clusterShow.
    *
    * They work as setOpacity(0) and setOpacity(1) respectively, but
@@ -1791,134 +1780,134 @@
    *
    */

    L.Marker.include({
        clusterHide: function() {
            var backup = this.options.opacity
            this.setOpacity(0)
            this.options.opacity = backup
            return this
        },
  L.Marker.include({
    clusterHide: function () {
      var backup = this.options.opacity
      this.setOpacity(0)
      this.options.opacity = backup
      return this
    },

        clusterShow: function() {
            return this.setOpacity(this.options.opacity)
        }
    })

    L.DistanceGrid = function(cellSize) {
        this._cellSize = cellSize
        this._sqCellSize = cellSize * cellSize
        this._grid = {}
        this._objectPoint = {}
    clusterShow: function () {
      return this.setOpacity(this.options.opacity)
    }
  })

    L.DistanceGrid.prototype = {
  L.DistanceGrid = function (cellSize) {
    this._cellSize = cellSize
    this._sqCellSize = cellSize * cellSize
    this._grid = {}
    this._objectPoint = {}
  }

        addObject: function(obj, point) {
            var x = this._getCoord(point.x),
                y = this._getCoord(point.y),
                grid = this._grid,
                row = grid[y] = grid[y] || {},
                cell = row[x] = row[x] || [],
                stamp = L.Util.stamp(obj)
  L.DistanceGrid.prototype = {

            this._objectPoint[stamp] = point
    addObject: function (obj, point) {
      var x = this._getCoord(point.x)
      var y = this._getCoord(point.y)
      var grid = this._grid
      var row = grid[y] = grid[y] || {}
      var cell = row[x] = row[x] || []
      var stamp = L.Util.stamp(obj)

            cell.push(obj)
        },
      this._objectPoint[stamp] = point

        updateObject: function(obj, point) {
            this.removeObject(obj)
            this.addObject(obj, point)
        },
      cell.push(obj)
    },

        //  Returns true if the object was found
        removeObject: function(obj, point) {
            var x = this._getCoord(point.x),
                y = this._getCoord(point.y),
                grid = this._grid,
                row = grid[y] = grid[y] || {},
                cell = row[x] = row[x] || [],
                i, len;
    updateObject: function (obj, point) {
      this.removeObject(obj)
      this.addObject(obj, point)
    },

            delete this._objectPoint[L.Util.stamp(obj)];
    //  Returns true if the object was found
    removeObject: function (obj, point) {
      var x = this._getCoord(point.x)
      var y = this._getCoord(point.y)
      var grid = this._grid
      var row = grid[y] = grid[y] || {}
      var cell = row[x] = row[x] || []
      var i; var len

            for (i = 0, len = cell.length; i < len; i++) {
                if (cell[i] === obj) {
                    cell.splice(i, 1)
      delete this._objectPoint[L.Util.stamp(obj)]

                    if (len === 1) {
                        delete row[x]
                    }
      for (i = 0, len = cell.length; i < len; i++) {
        if (cell[i] === obj) {
          cell.splice(i, 1)

                    return true
                }
            }
        },
          if (len === 1) {
            delete row[x]
          }

        eachObject: function(fn, context) {
            var i, j, k, len, row, cell, removed,
                grid = this._grid

            for (i in grid) {
                row = grid[i]

                for (j in row) {
                    cell = row[j]

                    for (k = 0, len = cell.length; k < len; k++) {
                        removed = fn.call(context, cell[k]);
                        if (removed) {
                            k--
                            len--
                        }
                    }
                }
            }
        },

        getNearObject: function(point) {
            var x = this._getCoord(point.x),
                y = this._getCoord(point.y),
                i, j, k, row, cell, len, obj, dist,
                objectPoint = this._objectPoint,
                closestDistSq = this._sqCellSize,
                closest = null

            for (i = y - 1; i <= y + 1; i++) {
                row = this._grid[i]
                if (row) {
                    for (j = x - 1; j <= x + 1; j++) {
                        cell = row[j]
                        if (cell) {
                            for (k = 0, len = cell.length; k < len; k++) {
                                obj = cell[k]
                                dist = this._sqDist(objectPoint[L.Util.stamp(obj)], point);
                                if (dist < closestDistSq ||
                                    dist <= closestDistSq && closest === null) {
                                    closestDistSq = dist
                                    closest = obj
                                }
                            }
                        }
                    }
                }
            }
            return closest
        },

        _getCoord: function(x) {
            var coord = Math.floor(x / this._cellSize)
            return isFinite(coord) ? coord : x
        },

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

    /* Copyright (c) 2012 the authors listed at the following URL, and/or
    eachObject: function (fn, context) {
      var i; var j; var k; var len; var row; var cell; var removed
      var grid = this._grid

      for (i in grid) {
        row = grid[i]

        for (j in row) {
          cell = row[j]

          for (k = 0, len = cell.length; k < len; k++) {
            removed = fn.call(context, cell[k])
            if (removed) {
              k--
              len--
            }
          }
        }
      }
    },

    getNearObject: function (point) {
      var x = this._getCoord(point.x)
      var y = this._getCoord(point.y)
      var i; var j; var k; var row; var cell; var len; var obj; var dist
      var objectPoint = this._objectPoint
      var closestDistSq = this._sqCellSize
      var closest = null

      for (i = y - 1; i <= y + 1; i++) {
        row = this._grid[i]
        if (row) {
          for (j = x - 1; j <= x + 1; j++) {
            cell = row[j]
            if (cell) {
              for (k = 0, len = cell.length; k < len; k++) {
                obj = cell[k]
                dist = this._sqDist(objectPoint[L.Util.stamp(obj)], point)
                if (dist < closestDistSq ||
                                    dist <= closestDistSq && closest === null) {
                  closestDistSq = dist
                  closest = obj
                }
              }
            }
          }
        }
      }
      return closest
    },

    _getCoord: function (x) {
      var coord = Math.floor(x / this._cellSize)
      return isFinite(coord) ? coord : x
    },

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

  /* Copyright (c) 2012 the authors listed at the following URL, and/or
    the authors of referenced articles or incorporated external code:
    http:// en.literateprograms.org/Quickhull_(Javascript)?action=history&offset=20120410175256

@@ -1944,629 +1933,628 @@
    Retrieved from: http:// en.literateprograms.org/Quickhull_(Javascript)?oldid=18434
    */

    (function() {
        L.QuickHull = {
  (function () {
    L.QuickHull = {

            /*
      /*
             * @param {Object} cpt a point to be measured from the baseline
             * @param {Array} bl the baseline, as represented by a two-element
             *   array of latlng objects.
             * @returns {Number} an approximate distance measure
             */
            getDistant: function(cpt, bl) {
                var vY = bl[1].lat - bl[0].lat,
                    vX = bl[0].lng - bl[1].lng
                return (vX * (cpt.lat - bl[0].lat) + vY * (cpt.lng - bl[0].lng))
            },
      getDistant: function (cpt, bl) {
        var vY = bl[1].lat - bl[0].lat
        var vX = bl[0].lng - bl[1].lng
        return (vX * (cpt.lat - bl[0].lat) + vY * (cpt.lng - bl[0].lng))
      },

            /*
      /*
             * @param {Array} baseLine a two-element array of latlng objects
             *   representing the baseline to project from
             * @param {Array} latLngs an array of latlng objects
             * @returns {Object} the maximum point and all new points to stay
             *   in consideration for the hull.
             */
            findMostDistantPointFromBaseLine: function(baseLine, latLngs) {
                var maxD = 0,
                    maxPt = null,
                    newPoints = [],
                    i, pt, d
      findMostDistantPointFromBaseLine: function (baseLine, latLngs) {
        var maxD = 0
        var maxPt = null
        var newPoints = []
        var i; var pt; var d

                for (i = latLngs.length - 1; i >= 0; i--) {
                    pt = latLngs[i]
                    d = this.getDistant(pt, baseLine)
        for (i = latLngs.length - 1; i >= 0; i--) {
          pt = latLngs[i]
          d = this.getDistant(pt, baseLine)

                    if (d > 0) {
                        newPoints.push(pt)
                    } else {
                        continue
                    }
          if (d > 0) {
            newPoints.push(pt)
          } else {
            continue
          }

                    if (d > maxD) {
                        maxD = d
                        maxPt = pt
                    }
                }
          if (d > maxD) {
            maxD = d
            maxPt = pt
          }
        }

                return { maxPoint: maxPt, newPoints: newPoints }
            },
        return { maxPoint: maxPt, newPoints: newPoints }
      },

            /*
      /*
             * Given a baseline, compute the convex hull of latLngs as an array
             * of latLngs.
             *
             * @param {Array} latLngs
             * @returns {Array}
             */
            buildConvexHull: function(baseLine, latLngs) {
                var convexHullBaseLines = [],
                    t = this.findMostDistantPointFromBaseLine(baseLine, latLngs);
      buildConvexHull: function (baseLine, latLngs) {
        var convexHullBaseLines = []
        var t = this.findMostDistantPointFromBaseLine(baseLine, latLngs)

                if (t.maxPoint) { //  if there is still a point "outside" the base line
                    convexHullBaseLines =
        if (t.maxPoint) { //  if there is still a point "outside" the base line
          convexHullBaseLines =
                        convexHullBaseLines.concat(
                            this.buildConvexHull([baseLine[0], t.maxPoint], t.newPoints)
                        );
                    convexHullBaseLines =
                        convexHullBaseLines.concat(
                            this.buildConvexHull([t.maxPoint, baseLine[1]], t.newPoints)
                          this.buildConvexHull([baseLine[0], t.maxPoint], t.newPoints)
                        )
                    return convexHullBaseLines
                } else { //  if there is no more point "outside" the base line, the current base line is part of the convex hull
                    return [baseLine[0]]
                }
            },
          convexHullBaseLines =
                        convexHullBaseLines.concat(
                          this.buildConvexHull([t.maxPoint, baseLine[1]], t.newPoints)
                        )
          return convexHullBaseLines
        } else { //  if there is no more point "outside" the base line, the current base line is part of the convex hull
          return [baseLine[0]]
        }
      },

            /*
      /*
             * Given an array of latlngs, compute a convex hull as an array
             * of latlngs
             *
             * @param {Array} latLngs
             * @returns {Array}
             */
            getConvexHull: function(latLngs) {
                //  find first baseline
                var maxLat = false, minLat = false,
                    maxLng = false, minLng = false,
                    maxLatPt = null, minLatPt = null,
                    maxLngPt = null, minLngPt = null,
                    maxPt = null, minPt = null,
                    i
      getConvexHull: function (latLngs) {
        //  find first baseline
        var maxLat = false; var minLat = false
        var maxLng = false; var minLng = false
        var maxLatPt = null; var minLatPt = null
        var maxLngPt = null; var minLngPt = null
        var maxPt = null; var minPt = null
        var i

                for (i = latLngs.length - 1; i >= 0; i--) {
                    var pt = latLngs[i]
                    if (maxLat === false || pt.lat > maxLat) {
                        maxLatPt = pt
                        maxLat = pt.lat
                    }
                    if (minLat === false || pt.lat < minLat) {
                        minLatPt = pt
                        minLat = pt.lat
                    }
                    if (maxLng === false || pt.lng > maxLng) {
                        maxLngPt = pt
                        maxLng = pt.lng
                    }
                    if (minLng === false || pt.lng < minLng) {
                        minLngPt = pt
                        minLng = pt.lng
                    }
                }

                if (minLat !== maxLat) {
                    minPt = minLatPt
                    maxPt = maxLatPt
                } else {
                    minPt = minLngPt
                    maxPt = maxLngPt
                }

                var ch = [].concat(this.buildConvexHull([minPt, maxPt], latLngs),
                    this.buildConvexHull([maxPt, minPt], latLngs))
                return ch
            }
        for (i = latLngs.length - 1; i >= 0; i--) {
          var pt = latLngs[i]
          if (maxLat === false || pt.lat > maxLat) {
            maxLatPt = pt
            maxLat = pt.lat
          }
          if (minLat === false || pt.lat < minLat) {
            minLatPt = pt
            minLat = pt.lat
          }
          if (maxLng === false || pt.lng > maxLng) {
            maxLngPt = pt
            maxLng = pt.lng
          }
          if (minLng === false || pt.lng < minLng) {
            minLngPt = pt
            minLng = pt.lng
          }
        }
    }())

    L.MarkerCluster.include({
        getConvexHull: function() {
            var childMarkers = this.getAllChildMarkers(),
                points = [],
                p, i

            for (i = childMarkers.length - 1; i >= 0; i--) {
                p = childMarkers[i].getLatLng()
                points.push(p)
            }

            return L.QuickHull.getConvexHull(points);
        if (minLat !== maxLat) {
          minPt = minLatPt
          maxPt = maxLatPt
        } else {
          minPt = minLngPt
          maxPt = maxLngPt
        }
    })

//  This code is 100% based on https:// github.com/jawj/OverlappingMarkerSpiderfier-Leaflet
//  Huge thanks to jawj for implementing it first to make my job easy :-)
        var ch = [].concat(this.buildConvexHull([minPt, maxPt], latLngs),
          this.buildConvexHull([maxPt, minPt], latLngs))
        return ch
      }
    }
  }())

    L.MarkerCluster.include({
  L.MarkerCluster.include({
    getConvexHull: function () {
      var childMarkers = this.getAllChildMarkers()
      var points = []
      var p; var i

        _2PI: Math.PI * 2,
        _circleFootSeparation: 25, //  related to circumference of circle
        _circleStartAngle: 0,
      for (i = childMarkers.length - 1; i >= 0; i--) {
        p = childMarkers[i].getLatLng()
        points.push(p)
      }

        _spiralFootSeparation: 28, //  related to size of spiral (experiment!)
        _spiralLengthStart: 11,
        _spiralLengthFactor: 5,
      return L.QuickHull.getConvexHull(points)
    }
  })

        _circleSpiralSwitchover: 9, //  show spiral instead of circle from this marker count upwards.
                                    //  0 -> always spiral; Infinity -> always circle
  //  This code is 100% based on https:// github.com/jawj/OverlappingMarkerSpiderfier-Leaflet
  //  Huge thanks to jawj for implementing it first to make my job easy :-)

        spiderfy: function() {
            if (this._group._spiderfied === this || this._group._inZoomAnimation) {
                return
            }
  L.MarkerCluster.include({

            var childMarkers = this.getAllChildMarkers(null, true),
                group = this._group,
                map = group._map,
                center = map.latLngToLayerPoint(this._latlng),
                positions;
    _2PI: Math.PI * 2,
    _circleFootSeparation: 25, //  related to circumference of circle
    _circleStartAngle: 0,

            this._group._unspiderfy();
            this._group._spiderfied = this;
    _spiralFootSeparation: 28, //  related to size of spiral (experiment!)
    _spiralLengthStart: 11,
    _spiralLengthFactor: 5,

            //  TODO Maybe: childMarkers order by distance to center
    _circleSpiralSwitchover: 9, //  show spiral instead of circle from this marker count upwards.
    //  0 -> always spiral; Infinity -> always circle

            if (childMarkers.length >= this._circleSpiralSwitchover) {
                positions = this._generatePointsSpiral(childMarkers.length, center)
            } else {
                center.y += 10 //  Otherwise circles look wrong => hack for standard blue icon, renders differently for other icons.
                positions = this._generatePointsCircle(childMarkers.length, center)
            }
    spiderfy: function () {
      if (this._group._spiderfied === this || this._group._inZoomAnimation) {
        return
      }

            this._animationSpiderfy(childMarkers, positions)
        },
      var childMarkers = this.getAllChildMarkers(null, true)
      var group = this._group
      var map = group._map
      var center = map.latLngToLayerPoint(this._latlng)
      var positions

        unspiderfy: function(zoomDetails) {
            //  <param Name="zoomDetails">Argument from zoomanim if being called in a zoom animation or null otherwise</param>
            if (this._group._inZoomAnimation) {
                return
            }
            this._animationUnspiderfy(zoomDetails)
      this._group._unspiderfy()
      this._group._spiderfied = this

            this._group._spiderfied = null
        },
      //  TODO Maybe: childMarkers order by distance to center

        _generatePointsCircle: function(count, centerPt) {
            var circumference = this._group.options.spiderfyDistanceMultiplier * this._circleFootSeparation * (2 + count),
                legLength = circumference / this._2PI, //  radius from circumference
                angleStep = this._2PI / count,
                res = [],
                i, angle
      if (childMarkers.length >= this._circleSpiralSwitchover) {
        positions = this._generatePointsSpiral(childMarkers.length, center)
      } else {
        center.y += 10 //  Otherwise circles look wrong => hack for standard blue icon, renders differently for other icons.
        positions = this._generatePointsCircle(childMarkers.length, center)
      }

            legLength = Math.max(legLength, 35) //  Minimum distance to get outside the cluster icon.
      this._animationSpiderfy(childMarkers, positions)
    },

            res.length = count
    unspiderfy: function (zoomDetails) {
      //  <param Name="zoomDetails">Argument from zoomanim if being called in a zoom animation or null otherwise</param>
      if (this._group._inZoomAnimation) {
        return
      }
      this._animationUnspiderfy(zoomDetails)

            for (i = 0; i < count; i++) { //  Clockwise, like spiral.
                angle = this._circleStartAngle + i * angleStep;
                res[i] = new L.Point(centerPt.x + legLength * Math.cos(angle), centerPt.y + legLength * Math.sin(angle))._round();
            }
      this._group._spiderfied = null
    },

            return res
        },
    _generatePointsCircle: function (count, centerPt) {
      var circumference = this._group.options.spiderfyDistanceMultiplier * this._circleFootSeparation * (2 + count)
      var legLength = circumference / this._2PI //  radius from circumference
      var angleStep = this._2PI / count
      var res = []
      var i; var angle

        _generatePointsSpiral: function(count, centerPt) {
            var spiderfyDistanceMultiplier = this._group.options.spiderfyDistanceMultiplier,
                legLength = spiderfyDistanceMultiplier * this._spiralLengthStart,
                separation = spiderfyDistanceMultiplier * this._spiralFootSeparation,
                lengthFactor = spiderfyDistanceMultiplier * this._spiralLengthFactor * this._2PI,
                angle = 0,
                res = [],
                i
      legLength = Math.max(legLength, 35) //  Minimum distance to get outside the cluster icon.

            res.length = count
      res.length = count

            //  Higher index, closer position to cluster center.
            for (i = count; i >= 0; i--) {
                //  Skip the first position, so that we are already farther from center and we avoid
                //  being under the default cluster icon (especially important for Circle Markers).
                if (i < count) {
                    res[i] = new L.Point(centerPt.x + legLength * Math.cos(angle), centerPt.y + legLength * Math.sin(angle))._round()
                }
                angle += separation / legLength + i * 0.0005
                legLength += lengthFactor / angle
            }
            return res;
        },
      for (i = 0; i < count; i++) { //  Clockwise, like spiral.
        angle = this._circleStartAngle + i * angleStep
        res[i] = new L.Point(centerPt.x + legLength * Math.cos(angle), centerPt.y + legLength * Math.sin(angle))._round()
      }

        _noanimationUnspiderfy: function() {
            var group = this._group,
                map = group._map,
                fg = group._featureGroup,
                childMarkers = this.getAllChildMarkers(null, true),
                m, i
      return res
    },

            group._ignoreMove = true
    _generatePointsSpiral: function (count, centerPt) {
      var spiderfyDistanceMultiplier = this._group.options.spiderfyDistanceMultiplier
      var legLength = spiderfyDistanceMultiplier * this._spiralLengthStart
      var separation = spiderfyDistanceMultiplier * this._spiralFootSeparation
      var lengthFactor = spiderfyDistanceMultiplier * this._spiralLengthFactor * this._2PI
      var angle = 0
      var res = []
      var i

            this.setOpacity(1)
            for (i = childMarkers.length - 1; i >= 0; i--) {
                m = childMarkers[i]
      res.length = count

                fg.removeLayer(m)

                if (m._preSpiderfyLatlng) {
                    m.setLatLng(m._preSpiderfyLatlng)
                    delete m._preSpiderfyLatlng
                }
                if (m.setZIndexOffset) {
                    m.setZIndexOffset(0)
                }

                if (m._spiderLeg) {
                    map.removeLayer(m._spiderLeg)
                    delete m._spiderLeg
                }
            }

            group.fire('unspiderfied', {
                cluster: this,
                markers: childMarkers
            })
            group._ignoreMove = false
            group._spiderfied = null
      //  Higher index, closer position to cluster center.
      for (i = count; i >= 0; i--) {
        //  Skip the first position, so that we are already farther from center and we avoid
        //  being under the default cluster icon (especially important for Circle Markers).
        if (i < count) {
          res[i] = new L.Point(centerPt.x + legLength * Math.cos(angle), centerPt.y + legLength * Math.sin(angle))._round()
        }
    })
        angle += separation / legLength + i * 0.0005
        legLength += lengthFactor / angle
      }
      return res
    },

//  Non Animated versions of everything
    L.MarkerClusterNonAnimated = L.MarkerCluster.extend({
        _animationSpiderfy: function(childMarkers, positions) {
            var group = this._group,
                map = group._map,
                fg = group._featureGroup,
                legOptions = this._group.options.spiderLegPolylineOptions,
                i, m, leg, newPos
    _noanimationUnspiderfy: function () {
      var group = this._group
      var map = group._map
      var fg = group._featureGroup
      var childMarkers = this.getAllChildMarkers(null, true)
      var m; var i

            group._ignoreMove = true
      group._ignoreMove = true

            //  Traverse in ascending order to make sure that inner circleMarkers are on top of further legs. Normal markers are re-ordered by newPosition.
            //  The reverse order trick no longer improves performance on modern browsers.
            for (i = 0; i < childMarkers.length; i++) {
                newPos = map.layerPointToLatLng(positions[i])
                m = childMarkers[i]
      this.setOpacity(1)
      for (i = childMarkers.length - 1; i >= 0; i--) {
        m = childMarkers[i]

                //  Add the leg before the marker, so that in case the latter is a circleMarker, the leg is behind it.
                leg = new L.Polyline([this._latlng, newPos], legOptions)
                map.addLayer(leg)
                m._spiderLeg = leg
        fg.removeLayer(m)

                //  Now add the marker.
                m._preSpiderfyLatlng = m._latlng
                m.setLatLng(newPos)
                if (m.setZIndexOffset) {
                    m.setZIndexOffset(1000000) //  Make these appear on top of EVERYTHING
                }

                fg.addLayer(m)
            }
            this.setOpacity(0.3)

            group._ignoreMove = false
            group.fire('spiderfied', {
                cluster: this,
                markers: childMarkers
            })
        },

        _animationUnspiderfy: function() {
            this._noanimationUnspiderfy()
        if (m._preSpiderfyLatlng) {
          m.setLatLng(m._preSpiderfyLatlng)
          delete m._preSpiderfyLatlng
        }
    })

//  Animated versions here
    L.MarkerCluster.include({

        _animationSpiderfy: function(childMarkers, positions) {
            var me = this,
                group = this._group,
                map = group._map,
                fg = group._featureGroup,
                thisLayerLatLng = this._latlng,
                thisLayerPos = map.latLngToLayerPoint(thisLayerLatLng),
                svg = L.Path.SVG,
                legOptions = L.extend({}, this._group.options.spiderLegPolylineOptions), //  Copy the options so that we can modify them for animation.
                finalLegOpacity = legOptions.opacity,
                i, m, leg, legPath, legLength, newPos

            if (finalLegOpacity === undefined) {
                finalLegOpacity = L.MarkerClusterGroup.prototype.options.spiderLegPolylineOptions.opacity;
            }

            if (svg) {
                //  If the initial opacity of the spider leg is not 0 then it appears before the animation starts.
                legOptions.opacity = 0

                //  Add the class for CSS transitions.
                legOptions.className = (legOptions.className || '') + ' leaflet-cluster-spider-leg'
            } else {
                //  Make sure we have a defined opacity.
                legOptions.opacity = finalLegOpacity
            }

            group._ignoreMove = true

            //  Add markers and spider legs to map, hidden at our center point.
            //  Traverse in ascending order to make sure that inner circleMarkers are on top of further legs. Normal markers are re-ordered by newPosition.
            //  The reverse order trick no longer improves performance on modern browsers.
            for (i = 0; i < childMarkers.length; i++) {
                m = childMarkers[i]

                newPos = map.layerPointToLatLng(positions[i])

                //  Add the leg before the marker, so that in case the latter is a circleMarker, the leg is behind it.
                leg = new L.Polyline([thisLayerLatLng, newPos], legOptions)
                map.addLayer(leg)
                m._spiderLeg = leg

                //  Explanations: https:// jakearchibald.com/2013/animated-line-drawing-svg/
                //  In our case the transition property is declared in the CSS file.
                if (svg) {
                    legPath = leg._path
                    legLength = legPath.getTotalLength() + 0.1 //  Need a small extra length to avoid remaining dot in Firefox.
                    legPath.style.strokeDasharray = legLength //  Just 1 length is enough, it will be duplicated.
                    legPath.style.strokeDashoffset = legLength
                }

                //  If it is a marker, add it now and we'll animate it out
                if (m.setZIndexOffset) {
                    m.setZIndexOffset(1000000) //  Make normal markers appear on top of EVERYTHING
                }
                if (m.clusterHide) {
                    m.clusterHide()
                }

                //  Vectors just get immediately added
                fg.addLayer(m)

                if (m._setPos) {
                    m._setPos(thisLayerPos)
                }
            }

            group._forceLayout()
            group._animationStart()

            //  Reveal markers and spider legs.
            for (i = childMarkers.length - 1; i >= 0; i--) {
                newPos = map.layerPointToLatLng(positions[i])
                m = childMarkers[i]

                //  Move marker to new position
                m._preSpiderfyLatlng = m._latlng
                m.setLatLng(newPos)

                if (m.clusterShow) {
                    m.clusterShow()
                }

                //  Animate leg (animation is actually delegated to CSS transition).
                if (svg) {
                    leg = m._spiderLeg
                    legPath = leg._path
                    legPath.style.strokeDashoffset = 0
                    //  legPath.style.strokeOpacity = finalLegOpacity;
                    leg.setStyle({ opacity: finalLegOpacity })
                }
            }
            this.setOpacity(0.3)

            group._ignoreMove = false

            setTimeout(function() {
                group._animationEnd()
                group.fire('spiderfied', {
                    cluster: me,
                    markers: childMarkers
                })
            }, 200)
        },

        _animationUnspiderfy: function(zoomDetails) {
            var me = this,
                group = this._group,
                map = group._map,
                fg = group._featureGroup,
                thisLayerPos = zoomDetails ? map._latLngToNewLayerPoint(this._latlng, zoomDetails.zoom, zoomDetails.center) : map.latLngToLayerPoint(this._latlng),
                childMarkers = this.getAllChildMarkers(null, true),
                svg = L.Path.SVG,
                m, i, leg, legPath, legLength, nonAnimatable

            group._ignoreMove = true
            group._animationStart()

            //  Make us visible and bring the child markers back in
            this.setOpacity(1)
            for (i = childMarkers.length - 1; i >= 0; i--) {
                m = childMarkers[i]

                //  Marker was added to us after we were spiderfied
                if (!m._preSpiderfyLatlng) {
                    continue
                }

                //  Close any popup on the marker first, otherwise setting the location of the marker will make the map scroll
                m.closePopup()

                //  Fix up the location to the real one
                m.setLatLng(m._preSpiderfyLatlng)
                delete m._preSpiderfyLatlng

                //  Hack override the location to be our center
                nonAnimatable = true
                if (m._setPos) {
                    m._setPos(thisLayerPos)
                    nonAnimatable = false
                }
                if (m.clusterHide) {
                    m.clusterHide()
                    nonAnimatable = false
                }
                if (nonAnimatable) {
                    fg.removeLayer(m)
                }

                //  Animate the spider leg back in (animation is actually delegated to CSS transition).
                if (svg) {
                    leg = m._spiderLeg
                    legPath = leg._path
                    legLength = legPath.getTotalLength() + 0.1
                    legPath.style.strokeDashoffset = legLength
                    leg.setStyle({ opacity: 0 })
                }
            }

            group._ignoreMove = false

            setTimeout(function() {
                //  If we have only <= one child left then that marker will be shown on the map so don't remove it!
                var stillThereChildCount = 0;
                for (i = childMarkers.length - 1; i >= 0; i--) {
                    m = childMarkers[i]
                    if (m._spiderLeg) {
                        stillThereChildCount++
                    }
                }

                for (i = childMarkers.length - 1; i >= 0; i--) {
                    m = childMarkers[i]

                    if (!m._spiderLeg) { //  Has already been unspiderfied
                        continue
                    }

                    if (m.clusterShow) {
                        m.clusterShow()
                    }
                    if (m.setZIndexOffset) {
                        m.setZIndexOffset(0)
                    }

                    if (stillThereChildCount > 1) {
                        fg.removeLayer(m)
                    }

                    map.removeLayer(m._spiderLeg)
                    delete m._spiderLeg
                }
                group._animationEnd()
                group.fire('unspiderfied', {
                    cluster: me,
                    markers: childMarkers
                })
            }, 200)
        if (m.setZIndexOffset) {
          m.setZIndexOffset(0)
        }
    })

    L.MarkerClusterGroup.include({
        //  The MarkerCluster currently spiderfied (if any)
        _spiderfied: null,

        unspiderfy: function() {
            this._unspiderfy.apply(this, arguments);
        },

        _spiderfierOnAdd: function() {
            this._map.on('click', this._unspiderfyWrapper, this)

            if (this._map.options.zoomAnimation) {
                this._map.on('zoomstart', this._unspiderfyZoomStart, this)
            }
            //  Browsers without zoomAnimation or a big zoom don't fire zoomstart
            this._map.on('zoomend', this._noanimationUnspiderfy, this)

            if (!L.Browser.touch) {
                this._map.getRenderer(this);
                //  Needs to happen in the pageload, not after, or animations don't work in webkit
                //  http:// stackoverflow.com/questions/8455200/svg-animate-with-dynamically-added-elements
                //  Disable on touch browsers as the animation messes up on a touch zoom and isn't very noticable
            }
        },

        _spiderfierOnRemove: function() {
            this._map.off('click', this._unspiderfyWrapper, this)
            this._map.off('zoomstart', this._unspiderfyZoomStart, this)
            this._map.off('zoomanim', this._unspiderfyZoomAnim, this)
            this._map.off('zoomend', this._noanimationUnspiderfy, this)

            //  Ensure that markers are back where they should be
            //  Use no animation to avoid a sticky leaflet-cluster-anim class on mapPane
            this._noanimationUnspiderfy()
        },

        //  On zoom start we add a zoomanim handler so that we are guaranteed to be last (after markers are animated)
        //  This means we can define the animation they do rather than Markers doing an animation to their actual location
        _unspiderfyZoomStart: function() {
            if (!this._map) { //  May have been removed from the map by a zoomEnd handler
                return
            }

            this._map.on('zoomanim', this._unspiderfyZoomAnim, this);
        },

        _unspiderfyZoomAnim: function(zoomDetails) {
            //  Wait until the first zoomanim after the user has finished touch-zooming before running the animation
            if (L.DomUtil.hasClass(this._map._mapPane, 'leaflet-touching')) {
                return
            }

            this._map.off('zoomanim', this._unspiderfyZoomAnim, this)
            this._unspiderfy(zoomDetails)
        },

        _unspiderfyWrapper: function() {
            //  <summary>_unspiderfy but passes no arguments</summary>
            this._unspiderfy()
        },

        _unspiderfy: function(zoomDetails) {
            if (this._spiderfied) {
                this._spiderfied.unspiderfy(zoomDetails)
            }
        },

        _noanimationUnspiderfy: function() {
            if (this._spiderfied) {
                this._spiderfied._noanimationUnspiderfy()
            }
        },

        //  If the given layer is currently being spiderfied then we unspiderfy it so it isn't on the map anymore etc
        _unspiderfyLayer: function(layer) {
            if (layer._spiderLeg) {
                this._featureGroup.removeLayer(layer)

                if (layer.clusterShow) {
                    layer.clusterShow()
                }
                //  Position will be fixed up immediately in _animationUnspiderfy
                if (layer.setZIndexOffset) {
                    layer.setZIndexOffset(0)
                }

                this._map.removeLayer(layer._spiderLeg)
                delete layer._spiderLeg
            }
        if (m._spiderLeg) {
          map.removeLayer(m._spiderLeg)
          delete m._spiderLeg
        }
    });
      }

    /**
      group.fire('unspiderfied', {
        cluster: this,
        markers: childMarkers
      })
      group._ignoreMove = false
      group._spiderfied = null
    }
  })

  //  Non Animated versions of everything
  L.MarkerClusterNonAnimated = L.MarkerCluster.extend({
    _animationSpiderfy: function (childMarkers, positions) {
      var group = this._group
      var map = group._map
      var fg = group._featureGroup
      var legOptions = this._group.options.spiderLegPolylineOptions
      var i; var m; var leg; var newPos

      group._ignoreMove = true

      //  Traverse in ascending order to make sure that inner circleMarkers are on top of further legs. Normal markers are re-ordered by newPosition.
      //  The reverse order trick no longer improves performance on modern browsers.
      for (i = 0; i < childMarkers.length; i++) {
        newPos = map.layerPointToLatLng(positions[i])
        m = childMarkers[i]

        //  Add the leg before the marker, so that in case the latter is a circleMarker, the leg is behind it.
        leg = new L.Polyline([this._latlng, newPos], legOptions)
        map.addLayer(leg)
        m._spiderLeg = leg

        //  Now add the marker.
        m._preSpiderfyLatlng = m._latlng
        m.setLatLng(newPos)
        if (m.setZIndexOffset) {
          m.setZIndexOffset(1000000) //  Make these appear on top of EVERYTHING
        }

        fg.addLayer(m)
      }
      this.setOpacity(0.3)

      group._ignoreMove = false
      group.fire('spiderfied', {
        cluster: this,
        markers: childMarkers
      })
    },

    _animationUnspiderfy: function () {
      this._noanimationUnspiderfy()
    }
  })

  //  Animated versions here
  L.MarkerCluster.include({

    _animationSpiderfy: function (childMarkers, positions) {
      var me = this
      var group = this._group
      var map = group._map
      var fg = group._featureGroup
      var thisLayerLatLng = this._latlng
      var thisLayerPos = map.latLngToLayerPoint(thisLayerLatLng)
      var svg = L.Path.SVG
      var legOptions = L.extend({}, this._group.options.spiderLegPolylineOptions) //  Copy the options so that we can modify them for animation.
      var finalLegOpacity = legOptions.opacity
      var i; var m; var leg; var legPath; var legLength; var newPos

      if (finalLegOpacity === undefined) {
        finalLegOpacity = L.MarkerClusterGroup.prototype.options.spiderLegPolylineOptions.opacity
      }

      if (svg) {
        //  If the initial opacity of the spider leg is not 0 then it appears before the animation starts.
        legOptions.opacity = 0

        //  Add the class for CSS transitions.
        legOptions.className = (legOptions.className || '') + ' leaflet-cluster-spider-leg'
      } else {
        //  Make sure we have a defined opacity.
        legOptions.opacity = finalLegOpacity
      }

      group._ignoreMove = true

      //  Add markers and spider legs to map, hidden at our center point.
      //  Traverse in ascending order to make sure that inner circleMarkers are on top of further legs. Normal markers are re-ordered by newPosition.
      //  The reverse order trick no longer improves performance on modern browsers.
      for (i = 0; i < childMarkers.length; i++) {
        m = childMarkers[i]

        newPos = map.layerPointToLatLng(positions[i])

        //  Add the leg before the marker, so that in case the latter is a circleMarker, the leg is behind it.
        leg = new L.Polyline([thisLayerLatLng, newPos], legOptions)
        map.addLayer(leg)
        m._spiderLeg = leg

        //  Explanations: https:// jakearchibald.com/2013/animated-line-drawing-svg/
        //  In our case the transition property is declared in the CSS file.
        if (svg) {
          legPath = leg._path
          legLength = legPath.getTotalLength() + 0.1 //  Need a small extra length to avoid remaining dot in Firefox.
          legPath.style.strokeDasharray = legLength //  Just 1 length is enough, it will be duplicated.
          legPath.style.strokeDashoffset = legLength
        }

        //  If it is a marker, add it now and we'll animate it out
        if (m.setZIndexOffset) {
          m.setZIndexOffset(1000000) //  Make normal markers appear on top of EVERYTHING
        }
        if (m.clusterHide) {
          m.clusterHide()
        }

        //  Vectors just get immediately added
        fg.addLayer(m)

        if (m._setPos) {
          m._setPos(thisLayerPos)
        }
      }

      group._forceLayout()
      group._animationStart()

      //  Reveal markers and spider legs.
      for (i = childMarkers.length - 1; i >= 0; i--) {
        newPos = map.layerPointToLatLng(positions[i])
        m = childMarkers[i]

        //  Move marker to new position
        m._preSpiderfyLatlng = m._latlng
        m.setLatLng(newPos)

        if (m.clusterShow) {
          m.clusterShow()
        }

        //  Animate leg (animation is actually delegated to CSS transition).
        if (svg) {
          leg = m._spiderLeg
          legPath = leg._path
          legPath.style.strokeDashoffset = 0
          //  legPath.style.strokeOpacity = finalLegOpacity;
          leg.setStyle({ opacity: finalLegOpacity })
        }
      }
      this.setOpacity(0.3)

      group._ignoreMove = false

      setTimeout(function () {
        group._animationEnd()
        group.fire('spiderfied', {
          cluster: me,
          markers: childMarkers
        })
      }, 200)
    },

    _animationUnspiderfy: function (zoomDetails) {
      var me = this
      var group = this._group
      var map = group._map
      var fg = group._featureGroup
      var thisLayerPos = zoomDetails ? map._latLngToNewLayerPoint(this._latlng, zoomDetails.zoom, zoomDetails.center) : map.latLngToLayerPoint(this._latlng)
      var childMarkers = this.getAllChildMarkers(null, true)
      var svg = L.Path.SVG
      var m; var i; var leg; var legPath; var legLength; var nonAnimatable

      group._ignoreMove = true
      group._animationStart()

      //  Make us visible and bring the child markers back in
      this.setOpacity(1)
      for (i = childMarkers.length - 1; i >= 0; i--) {
        m = childMarkers[i]

        //  Marker was added to us after we were spiderfied
        if (!m._preSpiderfyLatlng) {
          continue
        }

        //  Close any popup on the marker first, otherwise setting the location of the marker will make the map scroll
        m.closePopup()

        //  Fix up the location to the real one
        m.setLatLng(m._preSpiderfyLatlng)
        delete m._preSpiderfyLatlng

        //  Hack override the location to be our center
        nonAnimatable = true
        if (m._setPos) {
          m._setPos(thisLayerPos)
          nonAnimatable = false
        }
        if (m.clusterHide) {
          m.clusterHide()
          nonAnimatable = false
        }
        if (nonAnimatable) {
          fg.removeLayer(m)
        }

        //  Animate the spider leg back in (animation is actually delegated to CSS transition).
        if (svg) {
          leg = m._spiderLeg
          legPath = leg._path
          legLength = legPath.getTotalLength() + 0.1
          legPath.style.strokeDashoffset = legLength
          leg.setStyle({ opacity: 0 })
        }
      }

      group._ignoreMove = false

      setTimeout(function () {
        //  If we have only <= one child left then that marker will be shown on the map so don't remove it!
        var stillThereChildCount = 0
        for (i = childMarkers.length - 1; i >= 0; i--) {
          m = childMarkers[i]
          if (m._spiderLeg) {
            stillThereChildCount++
          }
        }

        for (i = childMarkers.length - 1; i >= 0; i--) {
          m = childMarkers[i]

          if (!m._spiderLeg) { //  Has already been unspiderfied
            continue
          }

          if (m.clusterShow) {
            m.clusterShow()
          }
          if (m.setZIndexOffset) {
            m.setZIndexOffset(0)
          }

          if (stillThereChildCount > 1) {
            fg.removeLayer(m)
          }

          map.removeLayer(m._spiderLeg)
          delete m._spiderLeg
        }
        group._animationEnd()
        group.fire('unspiderfied', {
          cluster: me,
          markers: childMarkers
        })
      }, 200)
    }
  })

  L.MarkerClusterGroup.include({
    //  The MarkerCluster currently spiderfied (if any)
    _spiderfied: null,

    unspiderfy: function () {
      this._unspiderfy.apply(this, arguments)
    },

    _spiderfierOnAdd: function () {
      this._map.on('click', this._unspiderfyWrapper, this)

      if (this._map.options.zoomAnimation) {
        this._map.on('zoomstart', this._unspiderfyZoomStart, this)
      }
      //  Browsers without zoomAnimation or a big zoom don't fire zoomstart
      this._map.on('zoomend', this._noanimationUnspiderfy, this)

      if (!L.Browser.touch) {
        this._map.getRenderer(this)
        //  Needs to happen in the pageload, not after, or animations don't work in webkit
        //  http:// stackoverflow.com/questions/8455200/svg-animate-with-dynamically-added-elements
        //  Disable on touch browsers as the animation messes up on a touch zoom and isn't very noticable
      }
    },

    _spiderfierOnRemove: function () {
      this._map.off('click', this._unspiderfyWrapper, this)
      this._map.off('zoomstart', this._unspiderfyZoomStart, this)
      this._map.off('zoomanim', this._unspiderfyZoomAnim, this)
      this._map.off('zoomend', this._noanimationUnspiderfy, this)

      //  Ensure that markers are back where they should be
      //  Use no animation to avoid a sticky leaflet-cluster-anim class on mapPane
      this._noanimationUnspiderfy()
    },

    //  On zoom start we add a zoomanim handler so that we are guaranteed to be last (after markers are animated)
    //  This means we can define the animation they do rather than Markers doing an animation to their actual location
    _unspiderfyZoomStart: function () {
      if (!this._map) { //  May have been removed from the map by a zoomEnd handler
        return
      }

      this._map.on('zoomanim', this._unspiderfyZoomAnim, this)
    },

    _unspiderfyZoomAnim: function (zoomDetails) {
      //  Wait until the first zoomanim after the user has finished touch-zooming before running the animation
      if (L.DomUtil.hasClass(this._map._mapPane, 'leaflet-touching')) {
        return
      }

      this._map.off('zoomanim', this._unspiderfyZoomAnim, this)
      this._unspiderfy(zoomDetails)
    },

    _unspiderfyWrapper: function () {
      //  <summary>_unspiderfy but passes no arguments</summary>
      this._unspiderfy()
    },

    _unspiderfy: function (zoomDetails) {
      if (this._spiderfied) {
        this._spiderfied.unspiderfy(zoomDetails)
      }
    },

    _noanimationUnspiderfy: function () {
      if (this._spiderfied) {
        this._spiderfied._noanimationUnspiderfy()
      }
    },

    //  If the given layer is currently being spiderfied then we unspiderfy it so it isn't on the map anymore etc
    _unspiderfyLayer: function (layer) {
      if (layer._spiderLeg) {
        this._featureGroup.removeLayer(layer)

        if (layer.clusterShow) {
          layer.clusterShow()
        }
        //  Position will be fixed up immediately in _animationUnspiderfy
        if (layer.setZIndexOffset) {
          layer.setZIndexOffset(0)
        }

        this._map.removeLayer(layer._spiderLeg)
        delete layer._spiderLeg
      }
    }
  })

  /**
     * Adds 1 public method to MCG and 1 to L.Marker to facilitate changing
     * markers' icon options and refreshing their icon and their parent clusters
     * accordingly (case where their iconCreateFunction uses data of childMarkers
     * to make up the cluster icon).
     */


    L.MarkerClusterGroup.include({
        /**
  L.MarkerClusterGroup.include({
    /**
         * Updates the icon of all clusters which are parents of the given marker(s).
         * In singleMarkerMode, also updates the given marker(s) icon.
         * @param layers L.MarkerClusterGroup|L.LayerGroup|Array(L.Marker)|Map(L.Marker)|
@@ -2574,105 +2562,104 @@
         * clusters need to be updated. If not provided, retrieves all child markers of this.
         * @returns {L.MarkerClusterGroup}
         */
        refreshClusters: function(layers) {
            if (!layers) {
                layers = this._topClusterLevel.getAllChildMarkers()
            } else if (layers instanceof L.MarkerClusterGroup) {
                layers = layers._topClusterLevel.getAllChildMarkers()
            } else if (layers instanceof L.LayerGroup) {
                layers = layers._layers
            } else if (layers instanceof L.MarkerCluster) {
                layers = layers.getAllChildMarkers()
            } else if (layers instanceof L.Marker) {
                layers = [layers]
            } //  else: must be an Array(L.Marker)|Map(L.Marker)
            this._flagParentsIconsNeedUpdate(layers)
            this._refreshClustersIcons()
    refreshClusters: function (layers) {
      if (!layers) {
        layers = this._topClusterLevel.getAllChildMarkers()
      } else if (layers instanceof L.MarkerClusterGroup) {
        layers = layers._topClusterLevel.getAllChildMarkers()
      } else if (layers instanceof L.LayerGroup) {
        layers = layers._layers
      } else if (layers instanceof L.MarkerCluster) {
        layers = layers.getAllChildMarkers()
      } else if (layers instanceof L.Marker) {
        layers = [layers]
      } //  else: must be an Array(L.Marker)|Map(L.Marker)
      this._flagParentsIconsNeedUpdate(layers)
      this._refreshClustersIcons()

            //  In case of singleMarkerMode, also re-draw the markers.
            if (this.options.singleMarkerMode) {
                this._refreshSingleMarkerModeMarkers(layers)
            }
      //  In case of singleMarkerMode, also re-draw the markers.
      if (this.options.singleMarkerMode) {
        this._refreshSingleMarkerModeMarkers(layers)
      }

            return this
        },
      return this
    },

        /**
    /**
         * Simply flags all parent clusters of the given markers as having a "dirty" icon.
         * @param layers Array(L.Marker)|Map(L.Marker) list of markers.
         * @private
         */
        _flagParentsIconsNeedUpdate: function(layers) {
            var id, parent
    _flagParentsIconsNeedUpdate: function (layers) {
      var id, parent

            //  Assumes layers is an Array or an Object whose prototype is non-enumerable.
            for (id in layers) {
                //  Flag parent clusters' icon as "dirty", all the way up.
                //  Dumb process that flags multiple times upper parents, but still
                //  much more efficient than trying to be smart and make short lists,
                //  at least in the case of a hierarchy following a power law:
                //  http:// jsperf.com/flag-nodes-in-power-hierarchy/2
                parent = layers[id].__parent
                while (parent) {
                    parent._iconNeedsUpdate = true
                    parent = parent.__parent
                }
            }
        },
      //  Assumes layers is an Array or an Object whose prototype is non-enumerable.
      for (id in layers) {
        //  Flag parent clusters' icon as "dirty", all the way up.
        //  Dumb process that flags multiple times upper parents, but still
        //  much more efficient than trying to be smart and make short lists,
        //  at least in the case of a hierarchy following a power law:
        //  http:// jsperf.com/flag-nodes-in-power-hierarchy/2
        parent = layers[id].__parent
        while (parent) {
          parent._iconNeedsUpdate = true
          parent = parent.__parent
        }
      }
    },

        /**
    /**
         * Re-draws the icon of the supplied markers.
         * To be used in singleMarkerMode only.
         * @param layers Array(L.Marker)|Map(L.Marker) list of markers.
         * @private
         */
        _refreshSingleMarkerModeMarkers: function(layers) {
            var id, layer
    _refreshSingleMarkerModeMarkers: function (layers) {
      var id, layer

            for (id in layers) {
                layer = layers[id]
      for (id in layers) {
        layer = layers[id]

                //  Make sure we do not override markers that do not belong to THIS group.
                if (this.hasLayer(layer)) {
                    //  Need to re-create the icon first, then re-draw the marker.
                    layer.setIcon(this._overrideMarkerIcon(layer))
                }
            }
        //  Make sure we do not override markers that do not belong to THIS group.
        if (this.hasLayer(layer)) {
          //  Need to re-create the icon first, then re-draw the marker.
          layer.setIcon(this._overrideMarkerIcon(layer))
        }
    });
      }
    }
  })

    L.Marker.include({
        /**
  L.Marker.include({
    /**
         * Updates the given options in the marker's icon and refreshes the marker.
         * @param options map object of icon options.
         * @param directlyRefreshClusters boolean (optional) true to trigger
         * MCG.refreshClustersOf() right away with this single marker.
         * @returns {L.Marker}
         */
        refreshIconOptions: function(options, directlyRefreshClusters) {
            var icon = this.options.icon
    refreshIconOptions: function (options, directlyRefreshClusters) {
      var icon = this.options.icon

            L.setOptions(icon, options)
      L.setOptions(icon, options)

            this.setIcon(icon)
      this.setIcon(icon)

            //  Shortcut to refresh the associated MCG clusters right away.
            //  To be used when refreshing a single marker.
            //  Otherwise, better use MCG.refreshClusters() once at the end with
            //  the list of modified markers.
            if (directlyRefreshClusters && this.__parent) {
                this.__parent._group.refreshClusters(this)
            }
      //  Shortcut to refresh the associated MCG clusters right away.
      //  To be used when refreshing a single marker.
      //  Otherwise, better use MCG.refreshClusters() once at the end with
      //  the list of modified markers.
      if (directlyRefreshClusters && this.__parent) {
        this.__parent._group.refreshClusters(this)
      }

            return this
        }
    })
      return this
    }
  })

    exports.MarkerClusterGroup = MarkerClusterGroup
    exports.MarkerCluster = MarkerCluster

  exports.MarkerClusterGroup = MarkerClusterGroup
  exports.MarkerCluster = MarkerCluster
}

export default {
    init
  init
}