code: function( elem, classNames ) {
  			if (elem.nodeType == 1)
  				elem.className = classNames !== undefined ?
  					jQuery.grep(elem.className.split(/\s+/), function(className){
  						return !jQuery.className.has( classNames, className );
  					}).join(" ") :
  					"";
  		}
docs: internal only, use removeClass("class")