If you're going to use code splitting with Webpack 2, you'll need to make sure the browser has support for the ES6
Promise API. This means that if you are required to support an old browser, you need to provide a polyfill. Polyfilling is relatively trivial to do with Webpack, but because Webpack itself depends on this particular polyfill, you have to come up with another way of doing so. In this lesson, we'll see how we can use the polyfill.io service to automatically polyfill this API (and others) for us.