// Copyright 2015 the V8 project authors. All rights reserved.// Use of this source code is governed by a BSD-style license that can be// found in the LICENSE file.vara=[0,1,2,,,,7];varproto={}a.__proto__=proto;varvisits=0;Array.prototype.forEach.call(a,(v,i,o)=>{++visits;proto[4]=4;});assertEquals(5,visits);