code: function(){
        if (!this.map){ return; }
        var options = $.extend(this.options.markerOptions, { map: this.map });
  
        if (options.disabled){ return; }
  
        this.marker = new google.maps.Marker(options);
  
        google.maps.event.addListener(
          this.marker,
          'dragend',
          $.proxy(this.markerDragged, this)
        );
      }
docs: Add a marker with the provided `markerOptions` but only if the option was set. Additionally it listens for the `dragend` event to notify the plugin about changes.