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// Copyright (C) 2016 the V8 project authors. All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.
/*---
es6id: 23.1.1
description: Subclassing the Map object
info: |
23.1.1 The Map Constructor
...
The Map constructor is designed to be subclassable. It may be used as the
value in an extends clause of a class definition. Subclass constructors that
intend to inherit the specified Map behaviour must include a super call to the
Map constructor to create and initialize the subclass instance with the
internal state necessary to support the Map.prototype built-in methods.
---*/
class M extends Map {}
var map = new M([{ 'foo': 'bar' }]);
assert.sameValue(map.size, 1);
map.set('bar', 'baz');
assert.sameValue(map.size, 2);
reportCompare(0, 0);