compatible with lower version browsers

[huanz]

please compile source code or not use const and arrow function

[sindresorhus]

This module mainly targets Node.js and newer browsers, not older browsers. It's up to you to transpile it with Babel if you want to use it in older browsers.

If you use Webpack, check out babel-engine-plugin, which transpiles only the dependencies that needs to be transpiled.

If you use Create React App, upgrade to Create React App v2. It supports automatic transpilation of dependencies, which will make this package just work.