add:  if (this.opacity != null) { marker.setOpacity(this.opacity); }  
context:     addMarker: function(marker) {        this.markers.push(marker);        if (this.map && this.map.getExtent()) {            marker.map = this.map;            this.drawMarker(marker);        }    },
meta: 1027	/local1/tlutelli/issta_data/temp/all_js/javascript/2007_temp/2007/1027/e3406bf0950b9ab95f4b48b22406a7a7a9e74ca8/Markers.js/clean/lib/OpenLayers/Layer/Markers.js