babel-preset-test-bundled-dependencies/node_modules/core-js/modules/_shared.js

Allow custom config for create-react-app without ejecting

var global = require('./_global')
  , SHARED = '__core-js_shared__'
  , store  = global[SHARED] || (global[SHARED] = {});
module.exports = function(key){
  return store[key] || (store[key] = {});
};