node_modules/core-js/modules/_set-species.js

'use strict';
var global = require('./_global');
var dP = require('./_object-dp');
var DESCRIPTORS = require('./_descriptors');
var SPECIES = require('./_wks')('species');

module.exports = function (KEY) {
  var C = global[KEY];
  if (DESCRIPTORS && C && !C[SPECIES]) dP.f(C, SPECIES, {
    configurable: true,
    get: function () { return this; }
  });
};