public/javascripts/yui/dom/dom-debug.js
function(el, className) {
            return Y.Dom.batch(el, Y.Dom._addClass, className);
        }
function(el, className) {
            return Y.Dom.batch(el, Y.Dom._addClass, className);
        }
function ( el , className ) { return Y . Dom . batch ( el , Y . Dom . _addClass , className ) ; }
Adds a class name to a given element or collection of elements.
@method addClass
@param {String | HTMLElement | Array} el The element or collection to add the class to
@param {String} className the class name to add to the class attribute
@return {Boolean | Array} A pass/fail boolean or array of booleans
Adds a class name to a given element or collection of elements .