code: function(marker) {
          this.markers.push(marker);
  
          if (this.opacity < 1) {
              marker.setOpacity(this.opacity);
          }
  
          if (this.map && this.map.getExtent()) {
              marker.map = this.map;
              this.drawMarker(marker);
          }
      }
docs: APIMethod: addMarker
  
  Parameters:
  marker - {<OpenLayers.Marker>}