2 // TODO: remove from `core-js@4`
3 var $ = require('../internals/export');
4 var IS_PURE = require('../internals/is-pure');
5 var $upsert = require('../internals/map-upsert');
7 // `WeakMap.prototype.upsert` method (replaced by `WeakMap.prototype.emplace`)
8 // https://github.com/tc39/proposal-upsert
9 $({ target: 'WeakMap', proto: true, real: true, forced: IS_PURE }, {