text: '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');
  }
  
  // using include in the callback selection requires a polyfill for ie
  require('string.prototype.includes');
  
  // some older browsers don't support Set, which apparently something compiles to
  require('core-js/fn/set');
  // ie 11 and old android don't have find
  require('core-js/fn/array/find');
  
  // seriously, not even map???
  require('core-js/es6/map');
  
  // 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');
  