PhantomJs: Can't find variable map : <p>I receive the following error:</p>

<pre><code>INFO [karma]: Karma v0.13.9 server started at http://localhost:9018/

INFO [launcher]: Starting browser PhantomJS

PhantomJS 1.9.8 (Mac OS X 0.0.0) ERROR
      ReferenceError: Can't find variable: Map
      at /Users/runtimeZero/code/vendor/inert/inert.min.js:589
</code></pre>

<p>I understand that I am including a file called <a href="https://raw.githubusercontent.com/WICG/inert/master/dist/inert.js" rel="noreferrer">inert.js</a> 
which is using ES6 Map() . This is freaking out PhantomJs.</p>

<p>So I included core-js/es6/map.js polyfill in my karma config under files. 
However that does not resolve the issue.</p>

<p>Any tips ?</p>
