code: function (options, directlyRefreshClusters) {
  		var icon = this.options.icon;
  
  		L.setOptions(icon, options);
  
  		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);
  		}
  
  		return this;
  	}
docs: 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}