// Copyright 2018 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.varlocales=["tlh","id","en"];varinput=["a","b","c"];varreferenceListFormat=newIntl.ListFormat(locales);varreferenceFormatted=referenceListFormat.format(input);classMyFormatextendsIntl.ListFormat{constructor(locales,options){super(locales,options);// could initialize MyListFormat properties}// could add methods to MyListFormat.prototype}varformat=newMyFormat(locales);varactual=format.format(input);assertEquals(actual,referenceFormatted);