text: /**
   * Copyright (c) 2015-present, Facebook, Inc.
   *
   * This source code is licensed under the MIT license found in the
   * LICENSE file in the root directory of this source tree.
   */
  'use strict';
  
  if (typeof Promise === 'undefined') {
    // Rejection tracking prevents a common issue where React gets into an
    // inconsistent state due to an error, but it gets swallowed by a Promise,
    // and the user has no idea what causes React's erratic future behavior.
    require('promise/lib/rejection-tracking').enable();
    window.Promise = require('promise/lib/es6-extensions.js');
  }
  
  // Make sure we're in a Browser-like environment before importing polyfills
  // This prevents `fetch()` from being imported in a Node test environment
  if (typeof window !== 'undefined') {
    // fetch() polyfill for making API calls.
    require('whatwg-fetch');
  }
  
  // Object.assign() is commonly used with React.
  // It will use the native implementation if it's present and isn't buggy.
  Object.assign = require('object-assign');
  
  // Support for...of (a commonly used syntax feature that requires Symbols)
  require('core-js/es6/symbol');
  // Support iterable spread (...Set, ...Map)
  require('core-js/fn/array/from');
  