How to use the raf.polyfill function in raf

// 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");
}

// 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");

// In tests, polyfill requestAnimationFrame since jsdom doesn't provide it yet.
// We don't polyfill it in the browser--this is user's responsibility.
if (process.env.NODE_ENV === "test") {
  require("raf").polyfill(global);
}

// 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');
}

// 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');

// In tests, polyfill requestAnimationFrame since jsdom doesn't provide it yet.
// We don't polyfill it in the browser--this is user's responsibility.
if (process.env.NODE_ENV === 'test') {
  require('raf').polyfill(global);
}

// 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');
}

// 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');

// In tests, polyfill requestAnimationFrame since jsdom doesn't provide it yet.
// We don't polyfill it in the browser--this is user's responsibility.
if (process.env.NODE_ENV === 'test') {
  require('raf').polyfill(global);
}

// 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');
}

// 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');

// In tests, polyfill requestAnimationFrame since jsdom doesn't provide it yet.
// We don't polyfill it in the browser--this is user's responsibility.
if (process.env.NODE_ENV === 'test') {
  require('raf').polyfill(global);
}

// 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');
}

// 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');

// In tests, polyfill requestAnimationFrame since jsdom doesn't provide it yet.
// We don't polyfill it in the browser--this is user's responsibility.
if (process.env.NODE_ENV === 'test') {
  require('raf').polyfill(global);
}

// 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");
}

// 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");

// In tests, polyfill requestAnimationFrame since jsdom doesn't provide it yet.
// We don't polyfill it in the browser--this is user's responsibility.
if (process.env.NODE_ENV === "test") {
  require("raf").polyfill(global);
}

// 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');
}

// 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');

// In tests, polyfill requestAnimationFrame since jsdom doesn't provide it yet.
// We don't polyfill it in the browser--this is user's responsibility.
if (process.env.NODE_ENV === 'test') {
  require('raf').polyfill(global);
}

// TODO(mattgoo): remove this polyfill and @babel/polyfill (in webpack.config.dev/.prod)
// once react chips is updated.
// classlist.contains, Array.from, includes, new Set() are not supported by IE11.
// https://github.com/material-components/material-components-web-react/issues/700
require('classlist-polyfill');

// 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');
}

// 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');

// In tests, polyfill requestAnimationFrame since jsdom doesn't provide it yet.
// We don't polyfill it in the browser--this is user's responsibility.
if (process.env.NODE_ENV === 'test') {
  require('raf').polyfill(global);
}

// 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');
}

// 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');

// In tests, polyfill requestAnimationFrame since jsdom doesn't provide it yet.
// We don't polyfill it in the browser--this is user's responsibility.
if (process.env.NODE_ENV === 'test') {
  require('raf').polyfill(global);
}

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');
}

// 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');

// In tests, polyfill requestAnimationFrame since jsdom doesn't provide it yet.
// We don't polyfill it in the browser--this is user's responsibility.
if (process.env.NODE_ENV === 'test') {
  require('raf').polyfill(global);
}