rem: return Element.classNames(element).add(className); 
add: Element.classNames(element).add(className); return element; 
context:   addClassName: function(element, className) {    if (!(element = $(element))) return;    return Element.classNames(element).add(className);  },
meta: 6601	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/6601/28b3187d07d97712c23182569a4d6fd00900b5f7/prototype.js/buggy/javascript/prototype/prototype.js