Ember CLI import ES6 file to ember-cli-builds.js

So the ember-cli-builds.js file clearly states

// If the library that you are including contains AMD or ES6
// modules that you would like to import into your application
// please specify an object with the list of modules as keys
// along with the exports of each module as its value.

I'm importing regular javascript files this way

app.import('vendor/global.js');

but what is the proper way to "specify an object with the list of modules as keys along with the exports of each module as it's value"?