2 var $ = require('../internals/export');
3 var IS_PURE = require('../internals/is-pure');
4 var emplace = require('../internals/map-emplace');
6 // `WeakMap.prototype.emplace` method
7 // https://github.com/tc39/proposal-upsert
8 $({ target: 'WeakMap', proto: true, real: true, forced: IS_PURE }, {