function Cluster(markerClusterer_) {
        this.markerClusterer_ = markerClusterer_;
        this.map_ = this.markerClusterer_.getMap();
        this.minClusterSize_ = this.markerClusterer_.getMinimumClusterSize();
        this.averageCenter_ = this.markerClusterer_.getAverageCenter();
        this.markers_ = []; // TODO: type;
        this.center_ = null;
        this.bounds_ = null;
        this.clusterIcon_ = new ClusterIcon(this, this.markerClusterer_.getStyles());
    }
/**
     *
     * @param markerClusterer_ The `MarkerClusterer` object with which this
     *  cluster is associated.
     */
@param markerClusterer_ The `MarkerClusterer` object with which this
cluster is associated.
@param markerClusterer_ The ` MarkerClusterer ` object with which this cluster is associated .
function Cluster(markerClusterer_) {
        this.markerClusterer_ = markerClusterer_;
        this.map_ = this.markerClusterer_.getMap();
        this.minClusterSize_ = this.markerClusterer_.getMinimumClusterSize();
        this.averageCenter_ = this.markerClusterer_.getAverageCenter();
        this.markers_ = []; 
        this.center_ = null;
        this.bounds_ = null;
        this.clusterIcon_ = new ClusterIcon(this, this.markerClusterer_.getStyles());
    }
function Cluster ( markerClusterer_ ) { this . markerClusterer_ = markerClusterer_ ; this . map_ = this . markerClusterer_ . getMap ( ) ; this . minClusterSize_ = this . markerClusterer_ . getMinimumClusterSize ( ) ; this . averageCenter_ = this . markerClusterer_ . getAverageCenter ( ) ; this . markers_ = [ ] ; this . center_ = null ; this . bounds_ = null ; this . clusterIcon_ = new ClusterIcon ( this , this . markerClusterer_ . getStyles ( ) ) ; }
@param markerClusterer_ The `MarkerClusterer` object with which this
  cluster is associated.
@param markerClusterer_ The ` MarkerClusterer ` object with which this cluster is associated .
// TODO: type;