| 1234567891011121314151617181920212223242526 | 'use strict';var $ = require('../internals/export');var getBuiltIn = require('../internals/get-built-in');var bind = require('../internals/function-bind-context');var call = require('../internals/function-call');var aCallable = require('../internals/a-callable');var anObject = require('../internals/an-object');var speciesConstructor = require('../internals/species-constructor');var getMapIterator = require('../internals/get-map-iterator');var iterate = require('../internals/iterate');// `Map.prototype.mapKeys` method// https://github.com/tc39/proposal-collection-methods$({ target: 'Map', proto: true, real: true, forced: true }, {  mapKeys: function mapKeys(callbackfn /* , thisArg */) {    var map = anObject(this);    var iterator = getMapIterator(map);    var boundFunction = bind(callbackfn, arguments.length > 1 ? arguments[1] : undefined);    var newMap = new (speciesConstructor(map, getBuiltIn('Map')))();    var setter = aCallable(newMap.set);    iterate(iterator, function (key, value) {      call(setter, newMap, boundFunction(value, key, map), value);    }, { AS_ENTRIES: true, IS_ITERATOR: true });    return newMap;  }});
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