rem: if (typeof args.last() == 'function') 
add: if (Object.isFunction(args.last())) 
context:   zip: function() {    var iterator = Prototype.K, args = $A(arguments);    if (typeof args.last() == 'function')      iterator = args.pop();    var collections = [this].concat(args).map($A);    return this.map(function(value, index) {      return iterator(collections.pluck(index));    });  },
meta: 9100	/local1/tlutelli/issta_data/temp/all_js/javascript/2007_temp/2007/9100/2d4247a14ff4ce25ad80cbc65b787dfde7ddb16e/prototype.js/buggy/typo3/contrib/prototype/prototype.js