rem: if (!this.hasStyleClass(className)) 
add: if (className && !this.hasStyleClass(className)) 
context: Element.prototype.addStyleClass = function(className) {    if (!this.hasStyleClass(className))        this.className += (this.className.length ? " " + className : className);}
meta: 5650	/local1/tlutelli/issta_data/temp/all_js/javascript/2007_temp/2007/5650/45903d337dcded71d4a013a1780651555e989aab/utilities.js/clean/WebCore/page/inspector/utilities.js