add: if (this._isLoaded || this._isErroneous) { return; }  
context: qx.Proto._onload = function(){  this._isLoaded = true;  this._isErroneous = false;  if (this.hasEventListeners(qx.constant.Event.LOAD)) {    this.dispatchEvent(new qx.event.type.Event(qx.constant.Event.LOAD), true);  }}
meta: 1005	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/1005/27be35015e5fe32d735625fa3333dbb30f2d0484/ImagePreloader.js/clean/qooxdoo/frontend/framework/source/class/qx/io/image/ImagePreloader.js