text: 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();
    global - require
    window.Promise = require('promise/lib/es6-extensions.js');
    global - require
  }
  
  // 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');
  